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Sakamoto, Luiz Maçao. "Estudo comparativo entre os aumentos das ferremias, determinados sem a administração prévia de ferro; após as administrações de sulfato ferroso, e complexo ferro-peptídeo." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/17/17138/tde-15072003-122244/.
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A deficiência de ferro e a anemia por deficiência de ferro (anemia ferropriva) são, ainda hoje, um dos maiores problemas nutricionais e de saúde pública em todo o mundo, afeta cerca de 2 bilhões de pessoas, especialmente nos países em desenvolvimento. Em geral os programas de prevenção e tratamento da anemia apresentam baixa adesão devido entre outros fatores a efeitos colaterais relacionados ao sistema gastrointestinal, resultantes da administração oral de compostos contendo ferro especialmente o sulfato ferroso. Dessa maneira, torna-se necessário o desenvolvimento de novas estratégias, compostos ou sistemas de liberação, que apresentem alta biodisponibilidade do ferro e minimizem ou eliminem os efeitos colaterais. Nesse sentido, o complexo ferro-peptídeo (CFP), devido as suas características físico-químicas que contrastam com aquelas apresentadas pelo sulfato ferroso (SF), torna-se uma possível alternativa como fonte de ferro. É um complexo orgânico com baixa solubilidade em pH ácido e totalmente solúvel em pH neutro a alcalino. Baseado nessas características, nos aumentos das ferremias (teores de ferro sérico ligado a apotransferrina) que ocorrem, em seres humanos, durante o período diurno observados por Wiltink et al. (1973) e no estudo realizado em ratos, por Dutra-de-Oliveira et al. (1995) comprovando resultados similares entre o sulfato ferroso e os complexos ferro-glicina e EDTA férrico, as hipóteses do presente estudo quando o complexo ferro-peptídeo é administrado por via oral, em homens saudáveis, foram: 1) induz aumentos significativos das ferremias quando comparados com os aumentos das ferremias controle (C), determinados sem a administração de ferro; 2) induz aumentos significativos iguais ou superiores aos determinados após a administração de sulfato ferroso utilizado como referência. Portanto, com o objetivo de testar as hipóteses, foram comparadas estatisticamente as variações das ferremias controle e as induzidas pelas administrações, de complexo ferro-peptídeo e sulfato ferroso. Essas variações foram determinadas a partir das diferenças entre as ferremias obtidas nas amostras coletadas de 10 homens adultos saudáveis, nos tempos: 30, 60, 120, 240, 480 e 720 minutos () e as obtidas no tempo zero, contados a partir do início da coleta. Cada voluntário submeteu-se aos tratamentos: recebeu no tempo 0, em jejum de 480, com intervalo de 7 dias, as seguintes quantidades de ferro: 0mg (C), 60mg (FP1) e 80mg (FP2) como CFP, 60mg como SF, permanecendo por mais 720 em jejum e 60mg como CFP com dieta isenta de inibidores de absorção de ferro durante e após a administração (FPD). O teste de Dunn demonstrou aumentos significativos das ferremias entre SFxC [60(p<0,01), 120(p<0,01), 240(p<0,01)], SFxFP1 [120(p<0,01), 240(p<0,05), 480(p<0,05)] e SFxFPD [240(p<0,01), 480(p<0,05)]. Entre as áreas sob as curvas ocorreram aumentos significativos nos intervalos de tempo: 0240 [SFxC (p<0,01), SFxFP1 (p<0,05)], 240720 [SFxFP1 (p<0,05), SFxFPD (p<0,05)] e 0720 [SFxC (p<0,05), SFxFP1 (p<0,05), SFxFPD (p<0,05)]. Conclusões: As hipóteses iniciais não foram confirmadas. Não foram significativos os aumentos das ferremias após as administrações do complexo ferro-peptídeo quando comparados com os aumentos das ferremias controle, nos respectivos tempos. Esses aumentos foram significativamente menores que os determinados após a administração de sulfato ferroso, com exceção aos decorrentes da administração de complexo ferro-peptídeo em quantidade equivalente a 80 mg de ferro.Iron deficiency and iron-deficiency anemia continue to be major nutritional and public health problems all over the world, affecting about 2 billion people, especially in developing countries. In general, programs for the prevention and treatment of anemia present low adhesion due, among other factors, to the side effects related to the gastrointestinal system resulting from the oral administration of iron-containing compounds, especially ferrous sulfate. Thus, it is necessary to develop new strategies, compounds or release systems presenting high iron bioavailability and minimizing or eliminating side effects. In this respect, the iron-peptide complex (IPC), due to its physicochemical characteristics differing from those of ferrous sulfate (FS), represents a possible alternative as a source of iron. It is an organic complex of low solubility at acid pH and fully soluble at neutral or alkaline pH. Based on these characteristics, on the increased blood iron concentrations (levels of serum iron bound to apotransferrin) occurring in human beings during the diurnal period as observed by Wiltink et al. (1973), and on the similar results obtained with FS and the iron-glycine and ferric EDTA complexes by Dutra-de-Oliveira et al. (1995) in a study on rats, the hypotheses tested in the present study in which the iron-peptide complex was administered orally to healthy men were: 1) the complex induces significant increases in blood iron concentrations compared to control (C) subjects receiving no iron administration; 2) induces significant increases equal to or higher than those obtained after administration of SF used as reference. Thus, in order to test these hypotheses, we compared statistically the variations in control blood iron concentrations and the concentrations induced by the administration of the iron-peptide complex and SF. The variations were determined from the difference between the blood iron concentrations obtained in samples collected from 10 healthy adult men at 30, 60, 120, 240, 480 and 720 minutes () and those obtained at time zero, counted starting from the beginning of collection. Each volunteer was submitted to the following treatments: at time 0, after a 480fast he received at 7 day intervals the following amounts of iron: 0 mg (C), 60 mg (FP1) and 80 mg (FP2) as IPC, and 60 mg as FS. He then fasted for an additional 720 and received 60 mg as IPC together with a diet free of inhibitors of iron absorption during and after administration (FPD). The Dunn test demonstrated significant increases in blood iron concentrations for FSxC [60(p<0.01), 120(p<0.01), 240(p<0.01)], FSxFP1 [120(p<0.01), 240(p<0.05), 480(p<0.05)] and FSxFPD [240(p<0.01), and 480(p<0.05)]. Significant increases occurred in the areas under the curve for the following comparisons at the following intervals: 0240 [FSxC (p<0.01), FSxFP1 (p<0.05)], 240720 [FSxFP1 (p<0.05), FSxFPD (p<0.05)] e 0720 [FSxC (p<0.05), FSxFP1 (p<0.05), and FSxFPD (p<0.05)]. Conclusions: The initial hypotheses were not confirmed since the increase in blood iron concentrations after the administration of the iron-peptide complex was not significant compared to the increase in control blood iron concentration at the respective time points. These increases were significantly lower than those obtained after SF administration, except for those obtained after the administration of the iron-peptide complex at a quantity equivalent to 80 mg iron.
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Marzak, Saïd. "Complexes du cuivre (i) construits sur le fragment (ms::(4))**(2-) (m=mo,w) : role du ligand thiocyanate dans l'edification de composes heterometalliques a structure infinie." Paris 6, 1988. http://www.theses.fr/1988PA066401.
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Preparation de complexes du type (nr::(4))::(n)(cu::(4)(ncs)::(4)ms::(4)), m=mo, w, r=me, et et n=2 ou 3. Selon la taille du cation, obtention de macrostructures bidimensionnelles ou tridimensionnelles; l'insertion du cation pph::(4)**(+) conduit a la formation d'une structure infinie de chaines lineaires
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Júnior, Antonio Carlos Roveda. "Reatividade química de um novo nitrosilsulfito complexo trans-[Ru(NH3)4(isn)(N(O)SO3)](PF6), e desenvolvimento de filmes de amido doadores de óxido nítrico." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/75/75135/tde-26072016-144608/.
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Na busca por novos materiais doadores de óxido nítrico (NO), o presente trabalho descreve o desenvolvimento de um filme à base de amido de mandioca, no qual foi incorporado um nitrosilo complexo de rutênio, e o estudo da liberação de NO nesse material. O nitrosilo complexo trans-[Ru(NH3)4(isn)NO](BF4)3 (RuNOisn; isn = isonicotinamida) apresenta a propriedade de liberar NO de forma controlada, por meio de fotólise (λirr = 310-370 nm) e de redução química. A incorporação desse complexo em filmes de amido foi realizada em condições brandas, resultando em um novo material para o armazenamento e liberação de NO, designado como CSx-RuNOisn. Os ensaios espectroscópicos indicaram que a esfera de coordenação do complexo RuNOisn permaneceu inalterada durante a produção dos filmes. A exposição de CSx-RuNOisn à luz (λirr = 355 nm) levou à liberação de NO e provavelmente à formação do fotoproduto trans [RuIII(NH3)4isn(H2O)]3+ no filme. A reação desse aquocomplexo de rutênio(III) com solução aquosa contendo nitrito de sódio regenerou o complexo de partida, RuNOisn. A identificação e quantificação do NO liberado durante a fotólise foi efetuada por meio da reação com oximioglobina. Durante o tempo de irradiação de 17 minutos, foram liberados 5,02 ± 0,12 μM de NO (10, 04 ± 0,24 nmol NO em 2 mL). Os ensaios de liberação de NO desencadeada por redução foram realizados utilizando-se L-cisteína como redutor. O fluxo de NO liberado a partir da reação com cisteína perdurou por mais de 7 horas, alcançando-se concentrações fisiologicamente relevantes, com fluxo médio de 1,9 pmol NO s-1 cm-2 de filme. Esse valor é comparável àquele produzido por células endoteliais, em que o fluxo de NO é de 1,67 pmol s-1 cm-2. Os resultados preliminares de degradação dos filmes in vivo sugerem que o material foi degradado pelo organismo em 30 dias. Todos os resultados alcançados sugerem que o filme CSx-RuNOisn é um candidato promissor para aplicações em meio biológico. Um novo complexo de rutênio contendo o ligante nitrosilsulfito (N(O)SO3 -) foi isolado, trans [Ru(NH3)4(isn)(N(O)SO3)](X) (isn = isonicotinamida, X = PF6- ou SiPF6 2-), e a sua estrutura cristalina determinada por difração de raio-X. A síntese desse complexo foi realizada por meio da reação entre trans-[Ru(NH3)4(isn)(NO)]3+ e íons sulfito (SO32-). O ataque nucleofílico do SO32- ocorreu no nitrogênio do ligante nitrosônio (NO) coordenado ao centro metálico de rutênio ([Ru-NO+]), originando o ligante O=N-SO3-: [RuNO+]3+ + SO32- →[Ru(N(O)SO3)]+. Observou-se que em meio aquoso, no intervalo de pH de 7,4 a 5,2 o complexo trans [Ru(NH3)4(isn)(N(O)SO3)]+ é estável, e a velocidade de decomposição (labilização do ligante isn) variou de k = 0,86 a 3,07 × 10-5 s-1. Em soluções mais ácidas (tampão ácido acético/acetato pH 4,2, 3,9, ou 1,0 M ácido trifluoroacético) o complexo trans-[Ru(NH3)4(isn)(N(O)SO3)]+ decompõe-se formando o respectivo nitrosilo complexo trans- [RuII(NH3)4(isn)NO+]3+. A reação do íon trans-[Ru(NH3)4(isn)(N(O)SO3)]+ com íons hidróxido (OH-) dá origem ao respectivo nitro complexo trans-[Ru(NH3)4(isn)(NO2)]+, que foi caracterizado por RMN de 15N e por espectroscopia eletrônica. As constantes de velocidade para essa reação são k = 6,16 ± 0,22 M-1 s-1 à T = 25oC, e k = 2,15 ± 0,07 M-1 s-1 à T = 15oC. A reação entre o nitrosilo complexo trans [RuII(NH3)4(isn)NO+]3+ e íons OH- também resulta na formação do nitro complexo trans-[Ru(NH3)4(isn)(NO2)]+. Neste caso, a constante de velocidade foi estimada entre k = 47-58 M-1 s-1 à T = 25oC, e o valor obtido experimentalmente à T = 15oC foi de k = 10,53 ± 0,29 M-1 s-1. O espectro eletrônico do íon complexo trans [Ru(NH3)4(isn)(N(O)SO3)]+ em meio aquoso apresentou uma banda larga com λ max = 362 nm (ε ∼6000 M-1 cm-1), atribuída por cálculos teóricos às seguintes transições: transferência de carga do metal para o ligante (TCML) Ru → N(O)SO3 e Ru → isn, e também d → d. Os ensaios preliminares de fotólise (λ irrad = 355 nm) do complexo trans[Ru(NH3)4(isn)(N(O)SO3)](PF6) em solução de tampão fosfato (pH 7,4) sugerem a formação das seguintes espécies nos intervalos iniciais de fotólise: i) NO, ii) SO3 •-, e iii) isn (labilizado do complexo). O mecanismo para a formação desses produtos ainda está sob investigação.Aiming the production of new nitric oxide releasing materials (NORM), this work reports the development of a cassava starch based film, in which a ruthenium nitrosyl complex was impregnated, and evaluate the NO release from this film. Ruthenium nitrosyl complex trans-[Ru(NH3)4(isn)NO](BF4)3 (RuNOisn; isn = isonicotinamide) is able to release NO in a controlled manner through both photolysis (λirr = 310-370 nm) and chemical reduction. The incorporation of such complex into the starch-based films was performed under mild conditions, yielding a new material able to store and release NO, abbreviated as CSx-RuNOisn. Spectroscopic analysis of CSx-RuNOisn indicated that the coordination sphere of RuNOisn remained intact during film production. Exposure of CSx-RuNOisn to long wave UV-light (λirr = 355 nm) leads to NO release and likely to the formation of the paramagnetic photoproduct trans-[RuIII(NH3)4isn(H2O)]3+ in the film. Reaction of this aquoruthenium(III) complex with aqueous nitrite regenerates RuNOisn in the film. Delivery of NO upon photolysis of CSx-RuNO isn was verified and quantified by trapping with oxymyoglobin. The calculated concentration of NO released from the film was 5.02 ± 0.12 μM (10.04 ± 0.24 nmol NO in a 2 mL) after approximately 17 min of irradiation (500 laser pulses at 2 s intervals). Moreover, NO release upon chemical reduction was carried out using L-cysteine as a reductant. Cysteine-mediated NO delivery from CSx-RuNOisn persisted for more than 7 h, during which physiologically relevant NO concentrations were liberated (average flux of 1.9 pmol NO s-1 cm-2 of film). This value is comparable to that produced by endothelial cells (1.67 pmol s-1 cm-2). Preliminary results about the biodegradation of the films in vivo suggest that the films were completely absorbed by the organism in a period of 30 days. These results suggest that CSx-RuNOisn is a promising candidate for use in biological applications. A new nitrosylsulphito complex bearing the ligand (N(O)SO3-) was isolated, trans-[Ru(NH3)4(isn)(N(O)SO3)](X) (isn = isonicotinamide, X = PF6- or SiPF6-), and its structure was determined by X-Ray crystallography. This complex was obtained by the reaction between trans-[Ru(NH3)4(isn)(NO)]3+ and sulfite ions (SO32-). X-Ray results confirmed that the nucleophilic attack of the sulphite anion (SO32-) was on the nitrogen atom of the nitrosyl ligand (NO) coordinated to the ruthenium center ([Ru-NO+]), yielding the ligand O=N-SO3-: [RuNO+]3+ + SO32- → [Ru(N(O)SO3)]+. Complex trans- [Ru(NH3)4(isn)(N(O)SO3)]+ is stable in aqueous solution from pH 7.4 to 5.2, and the decomposition rates (k) (due to the isn labilization) are in the range of k = 0.86-3.07 × 10-5 s-1. In more acidic conditions, (acetate buffer pH 4.2, 3.9, and trifluoroacetic acid solution 1.0 M) complex trans-[Ru(NH3)4(isn)(N(O)SO3)]+ is converted into the respective nitrosyl trans-[RuII(NH3)4(isn)NO+]3+. Reaction of trans-[Ru(NH3)4(isn)(N(O)SO3)]+ and hydroxide ions (OH-) yielded the nitro complex trans-[Ru(NH3)4(isn)(NO2)]+, which was characterized by 15N NMR and electronic spectroscopy. Rate constants for such reaction are k = 6.16 ± 0.22 M-1 s-1 at 25oC, and k = 2.15 ± 0.07 M-1 s-1 at 15oC. In the case of complex trans-[RuII(NH3)4(isn)NO+]3+, its reaction with OH- also yield the nitro complex trans-[Ru(NH3)4(isn)(NO2)]+. The estimated rate constant for such reaction was k = 46.9-57.6 M-1 s-1 at 25oC, and the experimental value obtained at 15oC was k = 10.53 ± 0.29 M-1 s-1. The ion complex trans-[Ru(NH3)4(isn)(N(O)SO3)]+ showed an intense and broad band at 362 nm (ε∼6000 M-1 cm-1) in aqueous solutions, which was assigned by DFT calculations to the following transitions: metal to ligand charge transfer (MLCT) Ru→N(O)SO3 and Ru→isn, and d→d as well. Preliminary photolysis assays (λirrad = 355 nm) performed with complex trans-[Ru(NH3)4(isn)(N(O)SO3)](PF6) in phosphate buffer solution (pH 7,4) suggests that the following species have been formed (in the initial photolysis period): i) NO, ii) SO3•-, and iii) isn (labilized). The whole mechanism to yield such products is still under investigation.
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Yvanes-Giuliani, Yliane. "Aluminium geochemistry in coastal lowland acid sulfate soils (CLASS) : speciation, reactivity and mobility." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4364.
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Ce projet de thèse vise à étudier les processus géochimiques de l'aluminium dans les sols acides à sulfates. Les résultats obtenus avec le dispositif de dialyse de Donnan montrent que l'aluminium dans la solution du sol est presque exclusivement (> 98%) présent sous forme de complexes de charge négative, vraisemblablement des organo-complexes d'aluminium. Les concentrations d'aluminium isotopiquement échangeables (valeurs-E) et les concentrations obtenues par extractions chimiques révèlent qu'une solution de 1 M KCl sous-estime systématiquement les valeurs E. Une méthode d'extraction séquentielle a révélé qu'une quantité importante de minéraux primaires (initialement présents dans les sols) a déjà été dissoute, comme en témoignent les concentrations élevées d'aluminium présentes en tant que minéraux secondaires d'aluminium. Ces études permettent de mieux comprendre la géochimie de l'aluminium dans les sols CLASS et de pouvoir intégrer ces connaissances dans la gestion des solsThe aim of this thesis was to further understanding on Al geochemistry in coastal lowland acid sulfate soils (CLASS). It was observed that Al was present almost solely (> 98%) as negatively charged complexes in CLASS pore-waters, presumably with natural organic matter. Isotopically exchangeable concentrations (E-values) of Al and extraction solutions used to estimate the exchangeable pool showed that 1 M KCl always underestimated isotopically exchangeable Al concentrations in these soils and that 0.2 M CuCl2 improved agreement between both methodologies but sometimes overestimated corresponding E values. A sequential extraction procedure showed that substantial amounts of Al have already been dissolved from primary aluminosilicates initially present in the soils and remain in the soils mostly as reactive secondary Al minerals. The outcomes of this thesis significantly further our understanding of Al geochemistry in CLASS environments and how this knowledge can be incorporated into land management practices
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Estienne, Jacques. "Des halogènes dans les édifices moléculaires étioniques : études cristallographiques, corrélations structure-réactivité, structure-conductivité, modèles structuraux." Aix-Marseille 1, 1986. http://www.theses.fr/1986AIX11001.
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Etude structurale de substances pouvant intervenir en tant que catalyseurs ou conducteurs electriques dans le monde industriel, dans le cadre de trois modeles : modele de l'atome cl mu -ponsteur co::(3) cl(c::(2)f::(3)o::(2))::(3)(so::(4))(c::(4)h::(10)o::(2))::(3) et mn::(4)cl::(4)(c::(2)f::(3)o::(2))::(4)(c::(4)h::(10)o)::(6), modele de l'ion tribromure dans des composes organiques et modele de l'iodure simple (iodures organiques comportant des dications diazoniatricycliques c::(14)h::(28)n::(2)**(2+). 2i**(-) et c::(15)h::(30)n::(2)**(2+). 2i**(-) et de l'ion iodoargentate (ag::(4) i::(8)**(4-). 2c::(15)h::(30)n::(2)**(2+))
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Ierno, Hélène. "Modélisation chimique de protéines fer-soufre : synthèses et caractérisations physico-chimiques de nouveaux agrégats à ligands imidazoles." Université Joseph Fourier (Grenoble ; 1971-2015), 1995. http://www.theses.fr/1995GRE10151.
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Durant ces dernieres annees, de nombreuses proteines fer-soufre ont ete decouvertes dont le site actif est relie a l'apoproteine par des ligands non-cysteinyles ; elles presentent des proprietes spectroscopiques et electrochimiques particulieres, liees a la nature des acides amines impliques dans la coordination du cur fer-soufre. Pour modeliser la coordination d'histidines sur les centres fer-soufre, nous avons prepare des agregats a ligands imidazoles neutres. Notre demarche synthetique fait intervenir des centres fer-soufre deja formes, a ligands halogenures, sur lesquels nous realisons une reaction d'echange de ligands. De premiers essais de coordination de ligands azotes neutres sur des agregats 2fe-2s nous ont amenes a definir certains criteres pour les ligands a cycles imidazoles en vue de leur coordination. L'utilisation de ces ligands nous a ensuite permis d'isoler de nouveaux composes fer-soufre qui presentent des proprietes oxydo-reductrices proches de celles des proteines fer-soufre a ligands histidines. Enfin, nous avons etudie la reactivite des ligands imidazoles par rapport a des agregats 4fe-4s
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Yu, Quanwei. "Ionene and ionene alkyl sulfate stoichiometric complexes." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2004. http://nbn-resolving.de/urn:nbn:de:swb:14-1099409249500-35629.
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Stoichiometric polyelectrolyte-surfactant complexes represent a type of comb-shaped polymers, in which every polymer chain unit has an electrostatically bound "side chain". These complexes are water-insoluble. In the solid state they assemble spontaneously into mesogenic structures. The [X,Y]-ionenes ([(CH2)XN+(CH3)2(CH2)YN+(CH3)2]nBr-2n) investigated formed stoichiometric complexes with alkyl sulfates. The ionene alkyl sulfate complexes display mesogenicity, i.e. optically isotropic dry complexes underwent lyotropic and thermotropic phase transitions to the optically anisotropic phase (and vice versa) under controlled relative humidity. The optically anisotropic phases exhibited hexagonal textures as revealed by polarizing microscopy. A new feature is the lyotropic transition brought about by the uptake of water through the gas phase. The complexes were all sensitive to both humidity and temperature. In principle, the effects can be applied to measure humidity.
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Wu, Danjun. "Multifunctional Chitosan-based Complexes for Nanomedicine." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10294.
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Ce travail est consacré à l'élaboration de nano-complexes polyélectrolytes (CPEs) ayant une stabilité améliorée en milieux physiologiques et à l'exemplification de leur fort potentiel d'application comme système de délivrance de (macro) molécules bioactives. Le chitosane comme polycation a été compléxé avec quatre polyanions naturels ayant différents densités de charges et groupements fonctionnels(-COO- et SO3-) à savoir l'acide hyaluronique (HYA), le chondroïtine sulfate (ChonS), le sulfate de dextrane (DS) et l'héparine (HEP). Les facteurs qui influent sur la formation et les propriétés physico-chimiques des nano-complexes chitosane-HYA ont été étudiés. Ces nanovecteurs perdent leur caractère colloïdal en milieux physiologiques. Pour améliorer leur stabilité dans ces conditions, une stratégie innovante qui implique l'ajout de zinc a été conçue. Cette stratégie de stabilisation a été démontrée comme étant polyvalente et a été étendue aux complexes polyélectrolytes (CPEs) chitosane-ChonS. Même si de cette manière une stabilité à long terme a été observée, cette stratégie reste uniquement applicable aux CPEs cationiques. Pour cette raison, une approche alternative permettant l'amélioration de la stabilité des colloïdes à charges positives ou négatives a été mise en oeuvre en concevant des nano-complexes de type coeur-couronne ternaires composés de polyacides forts c'est-à-dire de DS ou d'HEP associés au chitosane en coeur et un complexe chitosane-HYA en couronne. Tous les nano-complexes stables obtenus peuvent encapsuler le ténofovir, une molécule antirétrovirale et être fonctionnalisés par des IgAs de ciblage. En in vitro, ces nanovecteurs montrent une inhibition de l'infection des PBMC par le virus VIH-1 supérieure à l'antirétrovirale seuleThis work is devoted to the elaboration of nano-polyelectrolyte complexes (PECs) systems with improved stability in physiological media and to the establishment of their high potential of applications as bioactive (macro) molecule delivery systems. Chitosan as polycation were complexed with four natural polyanions of different charged groups and densities (-COO- and SO3 - as negative charges), namely hyaluronan (HYA), chondroitin sulfate (ChonS), dextran sulfate (DS) and heparin (HEP). The factors impacting the formation and physical-chemical properties of chitosan-HYA nanocomplexes were investigated. However, these nanovectors lost their colloidal character in physiological media. To improve their colloidal stability in physiological conditions, an innovative stabilization strategy was designed, involving zinc ion. This stabilization strategy proved versatile and was extended to chitosan-ChonS PECs. Though a long-term stability was achieved, this strategy was only applicable to cationic PECs. Therefore, an alternate approach enabled the improvement of the colloidal stability in physiological media of both positive and negative colloids by designing core-shell ternary polyelectrolyte nanocomplexes composed of strong polyacid (DS or HEP)-chitosan PECs as core and a chitosan-HYA complex as shell. Furthermore, all of the stabilized nanocomplexes allowed the encapsulation of active molecules anti-retroviral drug tenofovir and surface functionalization with targeting IgAs. In vitro, these nanovectors exhibited an inhibition of infection of PBMCs by HIV-1 virus which could be superior to the free drug
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Ramírez, Rivera Luis Miguel. "Síntese de complexos nanoestruturados formados por óxidos de ferro e sulfato de condroitina." reponame:Repositório Institucional da UnB, 2013. http://repositorio.unb.br/handle/10482/15741.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Nanociência e Nanobiotecnologia, 2013.Submitted by Alaíde Gonçalves dos Santos (alaide@unb.br) on 2014-06-02T15:52:30Z No. of bitstreams: 1 2013_LuisMiguelRamirezRivera.pdf: 12034472 bytes, checksum: 879d72b368bc5c71a7e0df5eebf90f5f (MD5)
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O objetivo desde projeto é sintetizar complexos nanoestruturados formados por óxidos de ferro e 4-sulfato de condroitina (4-SC). Dois métodos de síntese química foram empregados. No primeiro, nanopartículas de magnetita foram sintetizadas por meio da técnica de coprecipitação em meio aquoso, funcionalizadas com 4-sulfato de condroitina por meio da técnica de automontagem e em seguida dispersas em pH neutro. Na segunda rota de síntese, as nanopartículas de magnetita foram coprecipitadas na presença do 4-sulfato de condroitina e suspensas em meio aquoso com pH neutro. A espectroscopia Raman foi empregada para identificar a fase do óxido de ferro produzido, cujo resultado confirmou a síntese de magnetita. A análise dos espectros obtidos no infravermelho e dos dados de potencial zeta confirmaram a presença da cobertura de 4-sulfato de condroitina. Em adição, os resultados mostraram também diferenças no modo de interação do 4-SC com a superfície das partículas produzidas por meio dos diferentes métodos de síntese. Também foi realizado um monitoramento da estabilidade coloidal em meio biológico tais como a solução tampão fosfato (PBS) e meio de cultura DMEM. _______________________________________________________________________________________ ABSTRACT
The aim of this study is to produce nanostructured complexes of iron oxides and chondroitin-4-sulphate (C4S). Two synthesis routes were employed. On the first, magnetite nanoparticles were synthetized via the technique of coprecipitation in aqueous media, functionalized with chondroitin-4-sulphate via the layer-by-layer technique and then dispersed in neutral pH. On the second method, the magnetite nanoparticles were precipitated in the presence of chondroitin-4-sulphate and peptized in aqueous media with neutral pH. Raman spectroscopy was used to identify the iron oxide phase, confirming the synthesis of magnetite. The analysis of the infrared spectra and the data from zeta potential confirmed the presence of chondroitin-4-sulphate on the nanoparticles surface. In addition, the results indicated that the attachment of chondroitin-4-sulphate at the nanoparticle surface depends on the synthesis method. The colloidal stability was monitored in biological media, including phosphate buffer solution and DMEM culture medium.
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Cukiernik, Fabio D. "Synthèses, études physicochimiques et structurales de nouveaux matériaux moléculaires mésogènes : les carboxylates binucléaires de ruthénium." Grenoble 1, 1993. http://www.theses.fr/1993GRE10134.
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Nous avons synthetise et caracterise plusieurs series de carboxylates binucleaires de ruthenium a valence mixte de formule generale ru#2(rco#2)#4x, ou x=cl, rco#2, dodecylsulfate et r=ch#3(ch#2)#n, (c#nh#2#n#+#1o)#mph. Une serie de carboxylates de ruthenium divalent de formule ru#2(rco#2)#4 a chaine aliphatique lineaire a aussi ete synthetisee et etudiee. Les proprietes mesomorphes de ces produits ont ete etudiees par microscopie optique en lumiere polarisee, calorimetrie differentielle a balayage et diffraction de rayons x de poudre. Les carboxylates divalents presentent une mesophase colonnaire hexagonale ordonnee, tres similaire a celle qui avait ete obtenue pour les carboxylates de cuivre et de rhodium. Le mesomorphisme des carboxylates de ruthenium a valence mixte s'est revele fortement dependant de la nature de l'anion et du type de carboxylate. Le parametre clef dans l'apparition de mesophases est le remplissage efficace de l'espace, obtenu par utilisation d'anions a longue chaine ou de carboxylates equatoriaux encombrants. Un modele structural pour la mesophase colonnaire hexagonale des pentacarboxylates est propose. Les etudes spectroscopiques (infrarouge, raman) montrent que la vibration ru-ru est peu sensible a la nature des produits etudies. De plus, sa frequence reste pratiquement inchangee lors de la transition vers la phase cristal liquide. Le comportement magnetique des carboxylates de ruthenium a valence mixte est caracterise par un etat paramagnetique avec un fort ecart en champ nul. La presence d'interactions intermoleculaires depend de la nature de l'anion, ainsi que de certains parametres structuraux. Aucun changement de structure electronique n'a ete detecte pour les pentacarboxylates lors de la transition vers la mesophase, contrairement a la situation trouvee dans les carboxylates divalents. L'intercalation de pyrazine introduit des interactions intermoleculaires antiferromagnetiques dans les carboxylates a valence mixte, et conduit a la modification des proprietes spectroscopiques ainsi qu'a la perte du caractere mesogene des carboxylates divalents
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Lofi, Julia [Verfasser]. "Characterization of the Sulfite-Generating rDsrABL Complex of Allochromatium vinosum / Julia Lofi." Bonn : Universitäts- und Landesbibliothek Bonn, 2020. http://d-nb.info/1224966082/34.
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Le, Lay Luc. "Mise en forme et etude de filaments supraconducteurs a base de phases de chevrel." Rennes 1, 1988. http://www.theses.fr/1988REN10126.
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Elaboration et etude de filaments pbmo::(6)s::(8) et snmo::(6)s::(8) et des massifs de ces memes materiaux. Etude des comportements mecanique, chimique et supraconducteur des massifs. Optimisation de la composition de la poudre d'un brin monofilamentaire en fonction des dopants, de la stoechiometrie et de la nature des poudres de base. Optimisation des traitements des filaments: des traitements a haute temperature (950**(o)c a 1000**(o)cpounds et pendant des durees relativement courtes (0,5 a 2 h) permettent d'obtenir les meilleurs resultats de densites de courant critique. Realisation de bobinettes permettant d'atteindre des densites de courant critique de 10**(8) a/m**(2) a 14 t
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Carvalho, Luciana Batista de. "Autoxidação dos complexos de tetra, penta e hexaglicina de Ni(II), Co(II) e Cu(II) induzida por S(IV). Determinação de S(IV) e aldeídos por quimiluminescência." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-30032007-153520/.
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A autoxidação dos complexos de Ni(II) e Co(II) com tetra, penta e hexaglicina, em meio de tampão borato, é acelerada por espécies de enxofre (IV) (H2S0
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Moreno, Ruben Gregorio Moreno. "Estudos de lesão ao DNA promovida pela autoxidação de S(IV) na presença de complexos de Cu(III)/tetraglicina. Efeito sinérgico de Ni(II), Co(II) e Mn(II)." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-04062007-032229/.
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O presente trabalho apresenta estudos de lesão em biomoléculas (DNA e 2\'-deoxiguanosina) induzida por Cu(III)/tetraglicina (Cu(III)/G4), radicais de óxidos de enxofre (SO3·-, SO4·-, SO5·-), HO· e HSO5-, espécies estas geradas durante a autoxidação de S(IV) na presença de Cu(II)/G4 ou Cu(II) (ausência de tetraglicina) e traços de um segundo íon metálico (Ni(II), Co(II) ou Mn(II)). A formação dos radicais SO3·- e HO· foi detectada pela técnica de ressonância paramagnética eletrônica (EPR). As técnicas de espectrofotometria e dicroísmo circular foram empregadas para avaliar a formação de Cu(III)/G4 em diferentes condições experimentais, na presença e ausência de S(IV), e a interação entre os complexos de cobre (II)/(III) e a molécula de DNA. A eficiência da formação de Cu(III) depende da acidez, concentração de S(IV) e dos tampões utilizados. A lesão no DNA plasmidial pUC19 foi verificada empregando-se a técnica de eletroforese em gel de agarose. A extensão da lesão no DNA depende da acidez, concentração de S(IV), tempo de incubação e da presença de um segundo íon metálico. Usando a técnica de cromatografia líquida de alta eficiência (HPLC) foi possível estudar a oxidação de 2\'-deoxiguanosina a 8-oxo-7,8-dihidro-2\'-deoxiguanosina na presença dos oxidantes fortes gerados durante a autoxidação de S(IV) catalisada por Cu(II)/G4. Um estudo comparativo do efeito de vários íons metálicos evidenciou o sinergismo de Cu(II) e traços de um segundo íon metálico (Ni(II), Co(II) ou Mn(II), complexados ou não com tetraglicina).The present work presents studies related to biomolecules damage (DNA and 2\'-deoxyguanosine) induced by Cu(III)/tetraglycine (Cu(III)/G4), oxysulfur radicals (SO3·-, SO4·-, SO5·-) and HSO5-, species generated during S(IV) autoxidation in the presence of Cu(II)/G4 or Cu(II) (absence of tetraglycine) and trace level of a second metal ion (Ni(II), Co(II) or Mn(II)). The formation of SO3·- and HO· radicals was detected by electronic paramagnetic resonance technique (EPR). Spectrophotometric and circular dichroism techniques were used to evaluate the Cu(III)/G4 formation in different experimental conditions, in the presence and the absence of S(IV), and the interaction of copper (II)/(III) complexes and DNA molecule. The effectiveness of Cu(III) formation depends on the acidity, S(IV) concentration, and buffers used. The damage on pUC 19 plasmid DNA was verified by agarose gel electrophoresis. The extent on the DNA damage was related to acidity, S(IV) concentration, incubation time and to the presence of a second metal ion. Using the high performance liquid chromatography technique (HPLC) it was possible to study the oxidation of 2\'-deoxyguanosine to 8-oxo-7,8-dihydro-2\'-deoxyguanosine in the presence of strong oxidants generated during the S(IV) autoxidation catalyzed by Cu(II)/G4. A comparative study of the effect of several metal ions showed the synergism of Cu(II) and traces of a second metal ion (Ni(II), Co(II) or Mn(II), as tetraglycine complexes or not).
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Hintze, Vera, Sergey Samsonov, Sandra Rother, Sarah Vogel, Sebastian Köhling, Stephanie Moeller, Matthias Schnabelrauch, et al. "Sulfated Hyaluronan Derivatives Modulate TGF-β1:Receptor Complex Formation: Possible Consequences for TGF-β1 Signaling." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-230329.
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Glycosaminoglycans are known to bind biological mediators thereby modulating their biological activity. Sulfated hyaluronans (sHA) were reported to strongly interact with transforming growth factor (TGF)-β1 leading to impaired bioactivity in fibroblasts. The underlying mechanism is not fully elucidated yet. Examining the interaction of all components of the TGF-β1:receptor complex with sHA by surface plasmon resonance, we could show that highly sulfated HA (sHA3) blocks binding of TGF-β1 to its TGF-β receptor-I (TβR-I) and -II (TβR-II). However, sequential addition of sHA3 to the TβR-II/TGF-β1 complex led to a significantly stronger recruitment of TβR-I compared to a complex lacking sHA3, indicating that the order of binding events is very important. Molecular modeling suggested a possible molecular mechanism in which sHA3 could potentially favor the association of TβR-I when added sequentially. For the first time bioactivity of TGF-β1 in conjunction with sHA was investigated at the receptor level. TβR-I and, furthermore, Smad2 phosphorylation were decreased in the presence of sHA3 indicating the formation of an inactive signaling complex. The results contribute to an improved understanding of the interference of sHA3 with TGF-β1:receptor complex formation and will help to further improve the design of functional biomaterials that interfere with TGF-β1-driven skin fibrosis.
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Viselgienė, Gintarė. "The kinetics of silver electrodeposition from sulfite solutions." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20100623_093628-71686.
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Silver electrodeposition from sulfite electrolytes is considered to be one of the most promising processes to replace the extremely toxic traditional cyanide-based silver plating solutions with the additional advantage, that sulfite electrolytes can be successfully applied for silver deposition for micro-electro-mechanical systems (MEMSs). Mechanism of metal complexes electroreduction is an important result, especially when it may have a wide range of applications in the future. However, electrodeposition also has several shortcomings, including sulfite ion oxidation by oxygen in air and relatively negligible cathodic current densities, which are too low for qualitative galvanotechnique. There are very few works dedicated to the chemistry and electrochemistry of silver sulfite complexes. Most publications related with this subject are concerned with the questions of applicability. The main objective of this study was the investigation of the silver sulfite complexes electroreduction kinetics. To achieve this goal, we studied the dependence of the exchange current density on the free sulfite ions concentration in a series of isopotential solutions. Our studies also allowed to determine the mechanism of this electrochemical charge transfer reaction.Naudojant chronopotenciometrijos metodą buvo tirta sidabro elektronusodinimo iš sulfitinių tirpalų kinetika. Eksperimentiniai tyrimai patvirtino negausius žinomus literatūrinius duomenis, kad sidabro elektrokristalizacija iš sulfitinių elektrolitų yra apsprendžiama lėta sidabro ad-atomų kristalizacija galvaninės dangos paviršiuje. Tai ypač akivaizdu pusiausvyrinio potencialo srityje. Nustatyta, kad patikimiausi rezultatai, tiriant krūvio pernešimo stadiją, gaunami maksimaliai nutolus nuo pusiausvyros potencialo. Tai lengviausia realizuoti chronopotenciometrijos sąlygomis, o nustatytas mainų srovės tankis svyruoja tarp 0,9 (kai tirpalo sudėtis 0,003 ir 0,115 ) iki 2,46 (kai tirpalo sudėtis 0,1 ir 0,77 ). Patikimiausi rezultatai buvo gauti matuojant mainų srovės tankių priklausomybes nuo laisvų sulfito jonų koncentracijos izopotencialių ( 0,300 ) tirpalų serijoje. Visuose izopotencialiuose tirpaluose buvo nustatyti krūvio pernašos viršįtampiai -60 – -160 intervale. Naudojantis lygtimi ir mainų srovės tankio priklausomybės nuo laisvų sulfito jonų koncentracijos grafiku iš eksperimentinių duomenų nuolinkio kampo apskaičiuotas reakcijos laipsnis 0,67. Atsižvelgiant į galimas paklaidas, tikėtina, kad jis yra lygus 1. Gauti rezultatai rodo, kad artimas vienetui reakcijos laipsnis sulfito jonų atžvilgiu atitinka teiginį, jog betarpiškai fazių sąlyčio riboje redukuojasi kompleksinė dalelė . Atsiradusios paklaidos greičiausiai yra susiję su tirpalo komponentų... [toliau žr. visą tekstą]
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Johnson, Wyatt. "Metalloglycomics: Investigating the Interactions of Metal Complexes with Heparan Mimetics." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5672.
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Proteoglycans containing Heparan Sulfate (HS), a sulfated glycosaminoglycan (GAG), play a major role in the cell signaling process, interacting with many different proteins. HS is over expressed on the surface of many cancer cells. Enzymatic cleavage of HS-GAGs by heparanase causes release of angiogenic growth factors leading to tumor cell migration. Heparanase is also over-expressed in tumors with significant correlation between metastatic potential and heparanase activity. Proteoglycans and their associated enzymes are thus significant drug targets of high biological relevance.
A functional consequence of strong PPC-HS binding has been shown in proof-of-concept studies confirming inhibition of the model pentasaccharide, Fondaparinux, by bacterial Heparinase. Such metalloshielding by PPCs may also protect HS from enzymatic cleavage by the mammalian heparanase; preventing growth factors from binding to HS and/or preventing release of bound growth factors and thus inhibiting the metastatic response in the cancer cells. HS-GAGs are also receptors for cellular accumulation of cationic Polynuclear Platinum Complexes (PPCs) through high-affinity binding to the highly anionic HS. PPCs competitively inhibit uptake of TAMRA-R9, a fluorescent nona-arginine derivative, in CHO cells.
The previously reported series of Pt(II) complexes were investigated as DNA binders, initiating the apoptotic cascade. The result of PPC-DNA binding produces long range inter and intra-strand cross-links, that produce structural and conformational changes. Hydrogen bonding between phosphate oxygens and square planar Pt(II) nitrogen results in bidentate complexes by either backbone tracking or groove spanning of DNA. This complex forms a clamp like structure, called a phosphate clamp, similar to that of the arginine fork. Understanding this clamp allows us to investigate the structurally similar sulfate binding between metal complexes and target HSPG. HSPGs may allow significant research into both a novel cellular internalization of principal metals and “metalloshielding” of heparin by these compounds.
Previous studies have shown that a wide range of metal ions have high affinity to heparin. The trend of metal/heparin affinity is believed to be dependent on parameters consisting of the metal’s overall size, spatial orientation of the ligands attached to each metal, the net charge and oxidation state of these metals, and number of binding sites. Studies have shown relative affinities of sulfate and carboxylate groups for the metal ions. These metal cations play an important role in the affinity, specificity, and stability of many protein/heparin interactions. The study of simple coordination compounds, like Pt, Mn, V, Ru and Co, will allow preliminary results which will extend into the PPCs mode of binding.
This thesis focuses on the concept of metalloglycomics and reviews the interactions of various metal complexes with heparin. The covalent and non-covalent interactions of metal complexes with heparin resulting in strong bonding are explained through spectroscopy and calorimetry. The cleavage inhibition of heparanase by metal complexes is also described. Sulfate cluster anchoring shields the sulfates from loss as seen in mass spectrometry. The study of metalloglycomics offers potential understanding into the relevance of metal-heparin interactions and possibilities into the development of new compounds as therapeutic agents.
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Dias, João Rodrigo Vargas Pilla. "O Corpo várzea do macaco e as mineralizações de Cromo, Niquel e Cobre, Complexo Máficoultramáfico Jacurici, Cráton São Francisco, Bahia." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/88616.
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O Complexo Máfico-ultramáfico Jacurici, localizado na porção nordeste do cráton do São Francisco, consiste em vários corpos orientados N-S que hospedam o maior depósito de cromita do Brasil com mais de 40 Mt. Esses corpos estão segmentados espacialmente e podem representar uma única intrusão desmembrada tectonicamente, considerando que todos possuem uma espessa camada de cromitito maciço (de até 8 m). O corpo Várzea do Macaco está localizado na parte norte do complexo e também hospeda uma mineralização de Cu-Ni sulfetado. Este estudo descreve o corpo Várzea do Macaco e suas mineralizações e compara com os corpos mais ao sul (Ipueira-Medrado) onde uma evolução petrológica já foi estabelecida para o complexo. O corpo estudado esta invertido estratigraficamente e separado em 5 blocos, deslocados lateralmente por falhamentos tardios. É formado por dunito, lherzolito, piroxenito, olivina websterito, cromitito, gabronorito, com variadas intensidades de serpentinização e localmente está fortemente afetado por metamorfismo e metassomatismo. A mineralização sulfetada (Po±Pn±Cpy) está concentrada nas proximidades da camada de cromitito principal e ocorre de duas formas: uma primária magmática, com sulfetos intersticiais associados à olivina e piroxênio, variando de fino disseminado a grossos; ou como sulfetos remobilizados associados à zonas metassomáticas, onde vênulas e lentes de sulfetos interceptam a estratificação magmática e a foliação metamórfica. O intervalo onde sulfetos magmáticos e o minério de cromo ocorrem é caracterizado pela presença de anfibólio magmático, que possivelmente favoreceu o metamorfismo e as transformações metassomáticas posteriores que afetam mais intensamente este intervalo. Nas lentes de sulfetos remobilizados a calcopirita é levemente mais abundante, sugerindo um aumento na razão Cu/Ni. Comparado com Ipueira- Medrado, o Várzea do Macaco é significantemente enriquecido em clinopiroxênio, mas pode ser subdividido da mesma maneira. Possivelmente ambos os corpos fazem parte de um mesmo sistema intrusivo caracterizado por magmas primitivos com altos conteúdos de Mg e Ni. A contaminação crustal é considerada como gatilho para a mineralização de cromita. Por outro lado, na área de Várzea do Macaco o contaminante provavelmente foi diferente, o que permitiu a saturação de enxofre no corpo.The Jacurici Mafic-ultramafic Complex, located in the northeastern portion of the São Francisco craton, consists of several N-S oriented layered bodies that host the largest chromite deposit in Brazil (more than 40 Mt). These bodies are spatially separated and could represent a single intrusion tectonically disrupted, considering all bodies host a very thick (up to 8m) chromitite. The Várzea do Macaco body is located in the northern part of the Complex and also host a Ni-Cu sulfide mineralization. This study describes the Várzea do Macaco body and its mineralization in order to compare with the southern intrusions (Ipueira-Medrado) where a petrological evolution was previous established for the complex. The studied body is stratigraphically inverted and disrupted in five blocks, laterally dislocated by late faults. It is constituted by dunite, lherzolite, olivine webesterite, chromitite and gabbronorite with variable amount of serpentinization and is locally highly affected by metamorphism and metasomatism. The sulfide ore (Po±Pnd±Cpy) is concentrated spatially close to the main chromitite layer and occurs in two distinct circunstances: one primary magmatic with interstitial sulfides occurring associated with olivine and pyroxene and varying from fine disseminated to coarse grained; and as a remobilized ore, with sulfides associated to the metasomatic zones where coarse grained sulfide patches occur associated to veinlets or lenses that crosscut the primary layering. The interval where magmatic sulfide and chromitite ores occur is characterized by the presence of magmatic amphibole which possible favored late metamorphism and metassomatism transformation that affect more intensively this interval than the rest of the body. In the remobilized sulfide lenses and patches, the amount of chalcopyrite is higher suggesting a possible increase in the Cu/Ni ratio. Comparing to Ipueira- Medrado, the Varzea do Macaco is significantly enriched in clinopyroxene, but can be subdivided in the same way of the former. Possibly, both bodies are part of a single intrusive system characterized by a primitive magma with high Mg and Ni contents. The chromite mineralization are considered to be triggered by crustal contamination. On the other hand, the contaminant were possible distinct at Varzea do Macaco area allowing sulfide saturation.
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Wu, Yanlin. "Application of Fe(III)-EDDS complex in advanced oxidation processes : 4-ter-butylphenol degradation." Thesis, Clermont-Ferrand 2, 2014. http://www.theses.fr/2014CLF22455/document.
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Dans cette étude, un nouveau complexe de fer est utilisé dans des processus d’oxydation avancée pour la dégradation de polluants organiques présents dans l’eau. Le fer ferrique (Fe(III)) et l’acide éthylène diamine-N,N’-disuccinique (EDDS) forment un complexe Fe(III)-EDDS dont la structure a été mise en évidence durant ce travail. Les propriétés photochimiques du complexe ont ensuite été évaluées en fonction de différents paramètres physico-chimiques dont le pH qui est apparu comme un paramètre clé pour l’efficacité des processus testés. Ensuite nous avons donc travaillé sur l’utilisation de ce complexe dans les processus de Fenton modifié, photo-Fenton et comme activateur des persulfates (S2O82-). Nos expériences ont été réalisées en présence du 4-tert-butylphénol (4-t-BP) qui est connu pour être un perturbateur endocrinien. Nous avons ensuite mis en évidence les conditions optimales du traitement pour la dégradation du 4-t-BP. Il est apparu que le pH joue un rôle très important et qu’en présence de ce complexe de fer, l’efficacité est plus importante pour des pH neutre ou légèrement basique. L’identification des radicaux oxydants responsables de la dégradation du polluant a également été réalisée. Dans ce cadre nous avons montré que le radical sulfate joue un rôle plus important que le radical hydroxyle lors du processus d’activation des persulfatesAdvanced Oxidation Processes (AOPs) have been proved to be successfully applied in the treatment of sewage. It can decolorize the wastewater, reduce the toxicity of pollutants, convert the pollutants to be a biodegradable by-product and achieve the completed mineralization of the organic pollutants. The Fenton technologies which are performed by iron-activated hydrogen peroxide (H2O2) to produce hydroxyl radical (HO•) has been widely investigated in the past few decades. Recently, Sulfate radical (SO4•-) which was produced by the activation of persulfate (S2O82-) is applied to the degradation of organic pollutants in water and soil. It is a new technology recently developed. It is also believed to be one of the most promising advanced oxidation technologies.In this study, a new iron complex is introduced to the traditional Fenton reaction. The ferric iron (Fe(III)) and Ethylene diamine-N,N′-disuccinic acid (EDDS) formed the complex named Fe(III)-EDDS. It can overcome the main disadvantage of traditional Fenton technology, which is the fact that traditional Fenton technology can only perform high efficiency in acidic condition. Simultaneously, EDDS is biodegradable and it is one of the best environment-friendly complexing agents. On the other hand, the transition metal is able to activate S2O82- to generate SO4•-. Therefore, Fe(III)-EDDS will also be applied to activate S2O82- in the present study. 4-tert-Butylphenol (4-t-BP) has been chosen as a target pollutant in this study. It is widely used as a chemical raw material and is classified as endocrine disrupting chemicals due to the estrogenic effects. The 4-t-BP degradation rate (R4-t-BP) is used to indicate the efficiency of the advanced oxidation processes which are based on Fe(III)-EDDS utilization. The main contents and conclusions of this research are shown as follows:In the first part, the chemical structure and properties of Fe(III)-EDDS and the 4-t-BP degradation efficiency in UV/Fe(III)-EDDS system were studied. The results showed that Fe(III)-EDDS was a stable complex which was formed by the Fe(III) and EDDS with the molar ratio 1:1. From the photoredox process of Fe(III)-EDDS, the formation of hydroxyl radical was confirmed including that HO• is the main species responsible for the degradation of 4-t-BP in aqueous solution. Ferrous ion (Fe(II)) was also formed during the reaction. With the increasing Fe(III)-EDDS concentration, 4-t-BP degradation rate increased but is inhibited when the Fe(III)-EDDS concentration was too high. Indeed, Fe(III)-EDDS is the scavenger of HO•. pH value had a significant effect on the degradation efficiency of 4-t-BP that was enhanced under neutral or alkaline conditions. On the one hand, Fe(III)-EDDS presented in the FeL-, Fe(OH)L2-, Fe(OH)2L3-, Fe(OH)4- four different forms under different pH conditions and they had different sensitivity to the UV light. On the other hand, pH value affected the cycle between Fe(III) and Fe(II ). The formation of hydroperoxy radicals (HO2•) and superoxide radical anions (O2•-) (pka = 4.88) as a function of pH was also one of the reasons. It was observed that O2 was an important parameter affecting the efficiency of this process. This effect of O2 is mainly due to its important role during the oxidation of the first radical formed on the pollutant. (...)
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Sadir, Rabia. "Analyse dynamique des interactions interféron γ/récepteur et étude des processus d'internalisation : modèle de l'hormone de croissance et de l'interféron γ." Lyon 1, 1999. http://www.theses.fr/1999LYO1T061.
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Cândido, Manuela Chaves Loureiro. "Estudo da Reatividade dos íons complexos cis-[Ru(bpy)2(L)(NO)]n+ onde L=imidazol, 1-metilimidazol, tioureia e sulfito." reponame:Repositório Institucional da UFC, 2011. http://www.repositorio.ufc.br/handle/riufc/14978.
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CÂNDIDO, M. C. L Estudo da Reatividade dos íons complexos cis-[Ru(bpy)2(L)(NO)]n+ onde L=imidazol, 1-metilimidazol, tioureia e sulfito. 2011. 152 f. Dissertação (Mestrado em Química) - Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2011.Submitted by Daniel Eduardo Alencar da Silva (dealencar.silva@gmail.com) on 2014-11-24T21:51:51Z No. of bitstreams: 1 2011_dis_mclcandido.pdf: 1687505 bytes, checksum: 7c0fc11eb03e2db6af72e77dd6f309b6 (MD5)
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We carried out studies of chemical reactivity, electrochemistry and photochemistry of complexes cis-[Ru(bpy)2(L)(NO)](PF6)n, where L = imidazole, 1-methylimidazole, thiourea and sulfite. Were chosen, therefore, two ligands being donors and two with ligands that act as -recipient and the results indicated that the nature and strength of these ligands directly influence the strength of the back donation between the metal center and coordinated nitric oxide. The infrared spectra showed a characteristic frequency of nitric oxide coordinated as NO+, and there was variation in the observed value of frequency of NO stretching, dependant of the auxiliary ligand. The results indicate that the backbonding between Ru and NO+ is stronger in the complex featuring the sulfite ligand in the coordination sphere, that complex having a minimum value to that specific stretching frequency, when compared to the other complexes. The experimental data corroborate with the Lever parameter values for the ligands, indicating the contribution of them to the electron density of the metal. The cyclic voltammetry performed in aqueous media indicate that the reduction of NO+ species to NO0 is facilitated with the increase of electron density donation from auxiliary ligands to the metallic center. And the differential pulse voltammetry indicates the possibility of the formation of aqueous-complex from a chemical reaction, after coordinated NO+ reduction. This work have shown that the photochemical release of nitric oxide from the light stimulation of complex solutions is consistent, even being possible to determine the species formed as a product of the photolysis and subsequent calculations of quantum yield of NO0 realese. Quantification of nitric oxide release was performed indirectly, using the technique of square wave voltammetry, which was efficient for the purpose. It was also used a selective electrode for free NO0 molecule, confirming that irradiation of NO+ compounds solutions actually cause the release of coordinated nitric oxide (NO+) to its active form in biological environment.
Neste trabalho foram realizados estudos de reatividade química, eletroquímica e fotoquímica dos complexos cis-[Ru(bpy)2(L)(NO)](PF6)n, onde L= imidazol, 1-metilimidazol, tiouréia e sulfito. Foram escolhidos, portanto, dois ligantes auxiliares com características doadoras e dois com características receptoras e os resultados obtidos indicaram que a natureza e força destes ligantes influenciam diretamente na retrodoação existente entre o centro metálico e o óxido nítrico coordenado. Os espectros de infravermelho apresentaram freqüência característica de óxido nítrico coordenado na forma NO+, sendo que houve variação dos valores conforme a variação do ligante auxiliar. Os resultados indicam que a interação existente (retrodoação) entre o Ru e o NO é mais forte para o complexo que apresenta o ligante sulfito na esfera de coordenação, por apresentar um menor valor de freqüência de estiramento quando comparado aos demais complexos. Os dados experimentais corroboram com os valores do parâmetro de Lever encontrados para os ligantes, que indicam a contribuição dos mesmos para a densidade eletrônica do metal. Os ciclovoltamogramas, realizados em meio aquoso, indicam que a redução da espécie NO+ a NO0 é facilitada quanto maior for a doação de densidade eletrônica do ligante “L” para o centro metálico. E a voltametria de pulso diferencial indica a possibilidade da formação do aquo-complexo a partir de uma reação química após a redução de óxido nítrico. Os estudos fotoquímicos mostraram que a liberação de óxido nítrico a partir do estímulo luminoso de soluções dos complexos é consistente, sendo possível inclusive a determinação da espécie formada como produto da fotólise e posteriores cálculos de rendimento quântico da formação das mesmas. A quantificação da liberação de óxido nítrico foi realizada de maneira indireta, utilizando a técnica de voltametria de onda quadrada, que se mostrou eficiente para o objetivo. E foi utilizado também um eletrodo seletivo para a molécula de NO0 livre, confirmando que a irradiação das soluções realmente leva a liberação do óxido nítrico coordenado na sua forma ativa em meio biológico.
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Matussek, Julia. "Syntheses and Characterization of Polyimidosulfate Complexes." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2014. http://hdl.handle.net/11858/00-1735-0000-0022-5DB9-8.
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Matos, Vitor Bandeira Martins. "Geologia, petrologia e geoquímica do Corpo Ultramáfico Caboclo dos Mangueiros, noroeste da Bahia, e seu depósito de sulfeto de Ni-Cu." reponame:Repositório Institucional da UnB, 2017. http://repositorio.unb.br/handle/10482/31388.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Geociências, Programa de Pós-Graduação em Geologia, 2017.Submitted by Raquel Almeida (raquel.df13@gmail.com) on 2018-02-28T18:46:46Z No. of bitstreams: 1 2017_VitorBandeiraMartinsMatos.pdf: 3666067 bytes, checksum: 2cefcddd8fadb45a2bfe4f6faf23a5e8 (MD5)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).
O depósito magmático de sulfetos de Ni-Cu Caboclo dos Mangueiros representa recente descoberta feita pela Companhia Baiana de Pesquisa Mineral (CBPM) no ano de 2012, por meio de trabalhos exploratórios no extremo noroeste do estado da Bahia, próximo à divisa com o estado do Piauí. O depósito está situado na borda noroeste do Cráton do São Francisco, próximo à zona de contato com a faixa de dobramentos Neoproterozoica Rio Preto, região em que outros complexos máfico-ultramáficos (M-UM) mineralizados são encontrados, a exemplo do complexo M-UM Campo Alegre de Lourdes, mineralizado a Fe-Ti-V. Quinze furos de sondagem rotativa foram realizados, totalizando 2670 m, e indicaram recurso preliminar de aproximadamente 200Mt@0.20%Ni e 0.13%Cu. A sulfetação de Ni-Cu no depósito compreende um corpo de minério hospedado em intrusão de composição essencialmente ultramáfica com aproximadamente 2 km de comprimento na direção WNW-ESE, ~500 m de largura, chegando a 270 m de profundidade na porção central e ~100 m nas extremidades. A estrutura remete a um sill (soleira) alongado em forma de barco. Dados litogeoquímicos de rocha total indicam que a composição das rochas ultramáficas é controlada pelo tipo e proporção modal de minerais cúmulus. Gráficos dos óxidos selecionados de elementos maiores e menores versus MgO indicam predominância de olivina e clinopironênio cumulados. Estes por sua vez seguem a seguinte sequência de cristalização: Ol => Ol + Cpx => Cpx, indicando composição insaturada em sílica para o magma parental. A intrusão está fracionada da porção norte, onde dunito e wehrlito prevalecem, para a porção sul em que clinopiroxenito é abundante. O fracionamento é também observado no decréscimo progressivo dos valores de #Mg catiônico (i.e., Mg/[Mg+Fe2+]) de cristais cúmulus de clinopiroxênio em direção à porção sul da intrusão, como indicado pela variação de #Mg catiônico em clinopiroxênios de clinopiroxenito e wehrlito de furos de sondagem localizados na seção central perpendicular à intrusão (i.e., NE-SW). A variação composicional de #Mg catiônico nos clinopiroxênios é entre 0.78 e 0.94, sugerindo composição moderada a muito primitiva para o magma parental. Perfis de elementos terras raras e elementos traço resistentes à alteração, em gráficos normalizados ao manto primitivo, para as rochas cumuláticas ultramáficas mostram enriquecimento em elementos terras raras leves (ETRL) com significativas anomalias negativas de Nb e Ta. Este enriquecimento também é mostrado em perfis de elementos traço resistentes à alteração para o líquido parental estimado, embora anomalias negativas de Nb-Ta não são observadas. Os dados revelam que os padrões de ETRL são dependentes da proporção modal de clinopiroxênio nas rochas cumuláticas, como indicado pela diminuição progressiva nos valores da razão La/Sm (normalizados ao manto primitivo) de dunito, wehrlito, olivina-clinopiroxenito e clinopiroxenito. Significativa assimilação de rochas crustais não é suportada pela sequência de cristalização típica de magmas insaturados em sílica, bem como pela falta de anomalias negativas de Nb-Ta. A mineralização do depósito é dominantemente (i.e., ~99% em volume) de natureza primária e disseminada em forma de agregados (blebs) intersticiais, formando associações de pirrotita, pentlandita, calcopirita e pirita. A mineralização secundária consiste da remobilização e recristalização da mineralização primária e compreende em torno de 1% em volume do depósito. Ocorre em forma de brechas, vênulas ou ao longo do plano de foliação da rocha quando associadas a zonas de cisalhamento discretas. As texturas primárias e o conteúdo de sulfetos no depósito, acima da proporção considerada cotética numa intrusão mineralizada, sugerem entradas de magma carreando sulfetos em suspensão através de estrutura de conduto magmático que posteriormente se solidificou como um sill alongado em forma de barco. A saturação de sulfetos no magma é entendida como sendo decorrente da diminuição da temperatura, sem assimilação de rocha ou enxofre de origem crustal. Resultados das análises de isótopos de enxofre indicam composição isotópica para os sulfetos disseminados compatível com a composição isotópica do manto. Adicionalmente, o intervalo restrito dos valores da composição isotópica das amostras não sugere diferenças na composição isotópica relacionada a diferentes rochas (i.e., wehrlito ou clinopiroxenito) de diferentes locais da intrusão ultramáfica. O conteúdo depletado de elementos do grupo da platina na composição dos sulfetos, provenientes de magma parental primitivo, é sugestivo que tenha ocorrido segregação prévia de sulfetos em profundidade. Eventos tectônicos e metamorfismo em fácies xisto verde afetaram o sill fracionado e suas rochas crustais encaixantes. Apesar da tectônica, a estrutura magmática primária se manteve preservada. Devido à falta de idades absolutas para as rochas ultramáficas, o posicionamento do depósito Caboclo dos Mangueiros na evolução tectônica do cráton do São Francisco permanece incerto.
The Caboclo dos Mangueiros magmatic Ni-Cu sulfide deposit represents a recent discovery in the northern Brazil made by Companhia Baiana de Pesquisa Mineral (CBPM) in 2012 by means of greenfield exploration works at the northwestern portion of the Bahia state, close to the limit with the Piauí state. The deposit is situated in the northwestern edge of the São Francisco craton, close to the contact with the Rio Preto Neoproterozoic fold belt, where a cluster of mineralized mafic-ultramafic complexes are found, as exemplified by the Fe-Ti-V Campo Alegre de Lourdes mafic-ultramafic complex. Fifteen drill holes were performed, totalizing 2,670 meters, and indicate preliminary resource of ~ 200Mt@0.20%Ni and 0.13%Cu. The Ni-Cu sulfides comprise an orebody hosted in an ultramafic intrusion with ~2 km long WNW-ESE trending, ~500 m wide, reaching ~270 m depth in central portions and ~100 m in the extremities, resembling an elongated boat-shaped sill. The composition of the ultramafic rocks is controlled by the type and modal proportion of cumulus minerals. The plots of selected major and minor element oxides versus MgO indicate the predominance of olivine and clinopyroxene cumulates. It follows a crystallization sequence consisting of Ol => Ol + Cpx => Cpx, which indicate a silica undersaturated composition for the parental magma. The intrusion is fractionated from the northern portion, where dunite and wehrlite prevail, to the southern where clinopyroxenite is abundant. The fractionating also is observed in the progressively decrease of cationic Mg# values (i.e., Mg/[Mg+Fe2+]) in cumulus clinopyroxene crystals toward the southern portion of the intrusion, as indicated by the variation in cationic Mg# in clinopyroxene from clinopyroxenites and wehrlite from bore holes located across a NE-SW section of the intrusion. The compositional range of cationic Mg# of cumulus clinopyroxene from 0.78 to 0.94 supports a moderate to primitive composition for the parental magma. Primitive mantle-normalized REE and primitive mantle-normalized alteration-resistant trace element profiles for the cumulate ultramafic rocks show enrichment in LREE with significant negative Nb and Ta anomalies. This enrichment is also showed in mantle-normalized alteration-resistant trace element profiles estimated to the parental melt, although negative Nb-Ta anomalies are not observed. The data reveal that LREE patterns are dependent of the modal proportion of clinopyroxene in the cumulate rocks, as indicated by progressively lower La/SmPM from dunite, werhlite, olivine-clinopyroxenite and clinopyroxenite. Significant assimilation of crustal rocks during ascent and emplacement of the magma is not supported by the crystallization sequence typical of silica undersaturated magmas, as well as by the absence of Nb-Ta anomalies. The mineralization of the deposit is mainly (i.e., ~99 vol.%) primary nature and disseminated as interstitial blebs, comprising pyrrhotite, pentlandite, chalcopyrite and minor pyrite. The secondary mineralization consists of remobilization and recrystallization of the primary one and represent about 1 vol.% of the deposit. It occurs in irregular veinlets and breccia, as well as sulfide aggregates or stringers concordant with the foliation in discrete shear zones. The primary textures and the amount of sulfides, well above the cotectic proportion for a mineralized intrusion, suggest emplacement of sulfide droplets-charged magma through a conduit structure that later solidified as an elongated boat-shaped sill. The sulfide saturation of the magma is understood due to the decrease of temperature, with no significant assimilation of crustal-derived rock or sulfur. Results for sulfur isotope indicate isotopic compositions for disseminated sulfides that mainly fit into the mantle range. Additionally, the narrow compositional range of isotopic compositions in our samples does not suggest differences in isotopic compositions related to different host rocks (i.e., wehrlite or clinopyroxenite) of different location in the ultramafic intrusion. The depletion of PGE in the sulfide composition from a moderate to primitive magma is suggestive that has been occurred previous sulfide segregation at depth. Tectonic events and greenschist facies metamorphism may have affected the fractionated ultramafic sill and its sedimentary country rocks. Despite the tectonics the primary magmatic structure remains well preserved. Due to the lack of an absolute age for the ultramafic rocks the positioning of the Caboclo dos Mangueiros deposit in the tectonic evolution of the São Francisco craton remains uncertain.
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楊覺茵 and Kok-yan Yeung. "Syntheses, photophysics and photochemistry of alkynyl-, sulfido- and selenido- platinum(II) complexes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B31236388.
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Yeung, Kok-yan. "Syntheses, photophysics and photochemistry of alkynyl-, sulfido- and selenido- platinum(II) complexes /." Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B18597531.
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Sebastian, Maria Vespertina Alipazaga. "Estudo da autoxidação dos complexos de Cu(II), Ni(II) e Co(II)/tetraglicina induzida por S(IV)." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-19022018-162158/.
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O presente trabalho apresenta estudos espectrofotométricos relacionados à autoxidação dos complexos de Cu(II), Ni(II) e Co(II)/tetraglicina induzida por sulfito. Nossos estudos verificaram que a autoxidação de Cu(II)/tetraglicina (1,0x10-3 mol L-1) em pH = 9,0 (tampão borato) é afetada pela presença de traços de Ni(II) ou Co(II). Na ausência de Ni(II) ou Co(II), a reação é muito ineficiente e lenta com períodos de indução longos (aproximadamente 4 h). Ni(II) ou Co( II) em concentrações baixas ( 10-5 - 10-6 mol L-1) afetam significativamente a cinética: o período de indução diminui drasticamente (a menos de 2 s) e a formação de Cu(III) é fortemente acelerada com simultâneo aumento da eficiência da reação. A atividade catalítica e o sinergismo positivo de Co(II) e Ni(II) podem ser explicados pela oxidação mais rápida de Co(II) ou Ni(II)/tetraglicina pelo oxigênio dissolvido. O processo eletroquímico relacionado aos sistemas Cu(II)/Cu(III)/tetraglicina e Ni(II)/Ni(III)/tetraglicina são reversíveis, possibilitando monitorá-los adequadamente mediante o uso da técnica de eletrodo rotativo disco-anel. Entretanto, o sistema Co(II)/Co(III)/tetraglicina é irreversível. Esses estudos mostraram que as espécies de Cu(III) e Ni(III) geradas no eletrodo disco são instáveis nas condições experimentais empregadas. O efeito sinérgico positivo na presença de Ni(II) (que permitiu aumentar a sensibilidade) foi aproveitado para desenvolvimento de método espectrofotométrico e amperométrico simples e sensível para a determinação indireta de sulfito em meio aquoso. O método espectrofotométrico está baseado na medida de absorbância do complexo de Cu(III)/tetraglicina (gerado na presença de sulfito e traços de Ni(II)) em 365 nm. O método amperométrico em análise por injeção em fluxo baseia-se na medida de corrente (0,1 V vs Ag/AgCl) em função da concentração de Cu(III)/tetraglicina gerado quimicamente, na presença de sulfito e traços de Ni(II). Os métodos desenvolvidos foram empregados para a determinação de S(IV), em vinhos e sucos, após a sua extração da amostra acidificada, os resultados obtidos concordaram com aqueles obtidos pelo método iodométrico.The present work presents spectrophotometric studies related to the sulfite induced autoxidation of Cu(II), Ni(II) and Co(II)/tetraglycine complexes. The sulfite induced autoxidação of Cu(II)/tetraglycine (1.0x10-3 mol L-1) at pH = 9.0 (borate buffer) is affected by the presence of small quantities of the Ni(II) or Co(II). In the absence of added nickel (II) or cobalt (II), the reaction is very inefficient and slow with one large induction period (about 4 h). Trace amounts of Ni(II) or Co(II) (10-5 - 10-6 M) affect the kinetic significantly: the induction period drastically decreases (less than 2 s) and the formation of Cu(III) is strongly accelerated. The effectiveness of Cu(III) formation becomes much higher. The catalytic activity and the positive synergism of Co(II) and Ni(II) may be explained by the faster oxidation of Co(II) or Ni(II)/tetraglycine complexes by dissolved oxygen. The electrochemistry of Cu(II)/Cu(III)/tetraglycine and Ni(II)/Ni(III)/tetraglycine systems are reversible, such as it was possible to monitor them by using the rotating ring-disk electrode technique. However, the Co(II)/Co(III)/tetraglycine system is irreversible. Those studies showed that the Cu(III) and Ni(III) species generated on the disk electrode are unstable in the employed experimental conditions. The positive sinergistic effect in the presence of Ni(II) (which allowed to increase the sensibility) was taken in advantage for development of one simple and sensitive spectrophotometric and amperometric method for indirect determination of sulfite in aqueous medium. The spectrophotometric method is based on the absorbance measurement of the Cu(III)/tetraglicyne complex (generated in the presence of sulfite and small quantities of Ni(II)) at 365 nm. The amperometric method by flow injection analysis is based on the current measurement (0.1 V vs Ag/AgCl) as function of Cu(III)/tetraglycine concentration chemically generated, in the presence of sulfite and Ni(II). The methods were employed for the determination of S(IV), in wines and juices, after its extraction from acidified samples and the results were in agreement with those obtained by the iodometric procedure.
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Zhao, Shangqing. "Coumarin-based molecular probes : exploring the spectroscopic properties of complex mixtures and applications in colloid chemistry." Thesis, Linnéuniversitetet, Institutionen för kemi och biomedicin (KOB), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-79176.
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Warfarin is a well-known anticoagulant drug that is used to prevent cardiovascular disease and blood coagulation such as thrombosis. In this study, the main aim was to investigate the photo physical characteristics of warfarin in the different molecular environments provided by sodium dodecyl sulfate (SDS) micelles by using ultraviolet absorption and fluorescence emission spectroscopic techniques. Warfarin and a structural analogue not existing in solution as a cyclic hemiketal, phenprocoumon, were mixed with different concentrations of SDS and spectral changes for these warfarin and phenprocoumon were recorded. Interestingly, results demonstrated, based on an evident increase in the absorption intensity at 273 nm and an evident blue shift in the fluorescence emission spectrum after the addition of an increasing concentration of SDS, that primarily the cyclic hemiketal isomer of warfarin was found to be solvated by SDS micelles at an apparent recorded critical micelle concentration of ~8mM. Altogether these observations suggest that warfarin may be used as a molecular probe to explore the polarities of complex colloidal mixtures. Moreover, the possibility of using micelles for controlling the isomeric state of warfarin is interesting and can potentially be used for better controlling dosage of warfarin thereby reducing side effects.
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Aranha, Pedro Esteves. "Complexos de Cromo(III)-salen como catalisadores em reações de oxidação de sulfetos." Universidade Federal de São Carlos, 2009. https://repositorio.ufscar.br/handle/ufscar/6426.
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Previous issue date: 2009-02-06Universidade Federal de Sao Carlos
Transition metal complexes participate in many chemical processes. The study of these complexes is very interesting because of the diversified chemistry and great utility. Transition metal complexes act as catalysts in various homogenous and heterogeneous systems. The catalytic activity of these complexes is due to the presence of only one active metallic site for the catalytic reaction. Thus this type of reaction can be advantageous due to the elevated selectivity of the metal center. The new catalysts were characterized by melting point, elemental microanalyses, infrared and visible-ultraviolet spectra, molar conductance, magnetic susceptibility and mass spectra. The catalytic reaction of phenyl methyl sulfide to phenyl methyl sulfoxide and/or phenyl methyl sulfone was carried out in flasks, under agitation and temperature control, the progress of the reaction was monitored by gas chromatography. The catalytic results for reactions of oxidation of sulfide presented yields above 48% with PhIO as oxidant. Twelve catalysts were tested where four of them oxidizes successfully phenyl methyl sulfide into phenyl methyl sulfoxide. Specially the complex [Cr(3,5-Isalen)(H2O)2]Cl that yields 98.2% in this reaction. Another complexes tested had good results in the first hours of reaction but led to formation of sulfone after some time of reaction. It was observed that complexes containing only electron donor substituents groups para to hydroxyl of phenolic ring and complexes with esteric substituents groups ortho and para to hydroxyl of phenolic ring presented more selectivity as catalyst for the reaction of oxidation of sulfide.
Complexos de metais de transição têm participação em muitos processos químicos, sendo que a sua química diversificada e a grande utilidade fazem com que o estudo desses complexos torne-se muito interessante. Tais complexos atuam como catalisadores em vários sistemas homogêneos e heterogêneos. O fornecimento de um único sítio metálico para a ocorrência da reação catalisada favorece a atuação catalítica destes complexos, assim sendo, pode-se considerar este tipo de reação como vantajosa, devido à elevada seletividade do centro metálico. Esses novos potenciais catalisadores foram caracterizados por ponto de fusão, análise elementar, espectroscopia vibracional de absorção na região do infravermelho, espectroscopia de absorção na região ultravioleta-visível, medidas de condutividade, momento magnético e espectrometria de massas. As reações catalíticas de oxidação de fenilmetilsulfeto a fenilmetilsulfóxido e/ou fenilmetilsulfona foram realizadas em balões, sob agitação e temperatura controlada, sendo a quantificação dos produtos obtida com a técnica de cromatografia gasosa(GC). Os resultados das reações de oxidação de sulfeto apresentaram rendimentos acima de 48% com a utilização do oxidante PhIO sendo que quatro dos doze complexos testados conseguiram oxidar seletivamente o fenilmetilsulfeto a fenilmetilsulfóxido, se destacando o complexo [Cr(3,5-Isalen)(H2O)2]Cl que apresentou rendimento de 98,2%. Os demais complexos testados apresentaram boa reatividade nas primeiras horas da reação de oxidação, porém levaram também a formação da sulfona como produto após algum tempo de reação. Foi observado que complexos contendo somente grupos substituintes doadores de elétrons na posição para ao grupo hidroxila do anel e complexos contendo grupos substituintes que proporcionam efeitos estéricos nas posições orto e para ao grupo hidroxila apresentaram maior seletividade como catalisadores para a reação de oxidação de sulfeto.
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Hossain, G. M. Golzar. "Syntheses and structural studies of metal complexes of sulfa drugs." Thesis, Cardiff University, 2005. http://orca.cf.ac.uk/56117/.
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This thesis presents the results of the synthesis of metal complexes of sulfa drugs (sulfadiazine, sulfamerazine, sulfamethazine, sulfathiazole and sulfadimethoxine) with secondary ligands, which were subjected to X-ray crystallographic studies. The aim of this work was to synthesise metal complexes of sulfa drugs with secondary nitrogen donor ligands e.g. ammonia, pyridine (py), ethylenediamine (en), diethylenetriamine (dien), 2,2'- bipyridine, 1,10-phenanthroline, 4,4'-dimethyl-2,2'-bipyridine, A(3-aminopropyl)-bis- (ethylenediamine) (apen) and oxygen donor ligands such as, water and dimethylformamide (DMF) and to investigate the different modes of coordination of the sulfa drugs molecules to the metal ions in the presence of nitrogen/oxygen donor ligands. Chapter 1, details an introduction into the fundamental concepts, procedures and equipment involved in data collection, solution and refinement of single crystal structures. In Chapter 2, a review of the literature on the metal complexes of sulfa drugs along with the main aims of this work is presented. In Chapter 3, the general experimental procedure and synthetic methods have been described for the metal complexes of sulfa drugs whose results and discussion are described in chapter 4. In chapter 4, the crystal structure of sulfadiazine, a new polymorph of sulfamerazine and the syntheses of the metal complexes of sulfadiazine, sulfamerazine and sulfamethazine, their analytical and spectral data along with the X-ray structure determination of the complexes are presented. The complexes studied in this chapter are: A) Cobalt complex { Co(smz)2(H20) .DMF} (3) B) Nickel complexes Ni(en)3(sdz)2 .H20 (4) and Ni(smr)2(py)2 .4py (5) C) copper complexes Cu(en)2(sdz)2 (6), Cu(dien)2(sdz)2 (7), Cu(en)2(H20)2 smr)2 (8), Cu(en)2(H20)2 smr)2 .H20 (9), Cu2(smr)4 .2DMF (10), Cu2(smr)4 .2DMSO (11), Cu(smz)2(apen) .3H2O.CH3OH (12) and { Cu(smz)2.NH3 .2H20}w (13) D) Zinc complexes Zn(smz)2(NH3)2 (14) and Zn(smz)2(py)2 .2py (15), E) Cadmium complexes Cd(dien)2(sdz)2 .DMF (16), Cd(dien)(smr)2 .H20 (17), Cd(sdz)2(bpy) (18), Cd(sdz)2(phen) (19), Cd(sdz)2(dmbpy) .2DMF (20), Cd(smr)2(phen) (21), { Cd(smz)2(H20) .DMF}/I (22), { Cd(smz)2(H20) .2H20} (23) and Cd(smz)2(en) .2DMF (24) and F) Mercury complexes Hg(sdz)2(DMF)2 (25), Hg(smr)2 (26) Hg(smr)2(bpy) (27) and Hg(smz)2(DMF)2 (28). The structural results for the complexes are discussed and compared with other related complexes. In this context, the different types of coordination geometries, important parameters within the coordination sphere, the various modes of coordination of the sulfa drugs in the anionic form, dimeric polymeric complexes, the role of hydrogen bonds in the formation of the "cation-anion pair" and the packing diagram have been discussed. In Chapter 5, we have described the syntheses and characterisation of the complexes of sulfathiazole, their analytical and spectral data along with the X-ray structure determination of these complexes are presented. The complexes studied are: (H2stz)2 N03 .H20 (29), CoCl4 (H2stz)2 .CH3COOH (30) and Cu(en)2(H20)2 stz)2 .2H20 (31). In all the complexes the sulfathiazole molecules act as ionic species. The structural results for the complexes are discussed and compared with other related complexes. In this context, the role of hydrogen bonds in the formation of the "cation-anion pair" and the packing diagram has been discussed. Chapter 6 describes the structure of sulfadimethoxine and synthesis and characterisation of a zinc complex of sulfadimethoxine Zn(sdm)2(NH3)2 .2H20 (33) by analytical and spectral data along with the X-ray structure determination. The structural results of the complex are discussed and compared with other related complexes. The packing diagram of the complex with the hydrogen bonds is discussed in this chapter.
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Jaffuel, Aurore. "Résolution de mélanges complexes d'oligosaccharides sulfatés par chromatographie 2D et spectrométrie de masse : application aux héparines thérapeutiques." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1150.
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Loza, Kateryna [Verfasser], and Matthias [Akademischer Betreuer] Epple. "Behavior of toxicologically relevant silver compounds and barium sulfate particles in complex media : from synthesis to biological investigations / Kateryna Loza. Betreuer: Matthias Epple." Duisburg, 2016. http://d-nb.info/1099910307/34.
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Gerth, Lutz Martin. "Électrodéposition de cuivre à partir de solutions sulfuriques : mesures locales de la densité de courant dans des cellules à hydrodynamique complexe." Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL153N.
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Ce travail se situe dans le cadre d'un programme européen ayant pour objet l'élaboration d'un code de calcul pour la prédiction de distributions de densité de courant, de potentiel et de courant dans un réacteur électrochimique. Notre contribution concerne l'obtention de données expérimentales pour le développement et la validation de ce code: l'exemple de l'électrodéposition de cuivre en milieu sulfaté a été choisi comme réaction test. Dans un premier temps, nous avons déterminé les données physico-chimiques du système considéré ; à l'aide de techniques électrochimiques complémentaires, nous avons mis en évidence l'importance de la préparation de la surface d'électrode. L’ensemble des résultats communiqué à nos partenaires a rendu possible la prédiction de distributions dans différentes configurations. Dans un deuxième temps, les réactions ont été mises en œuvre dans deux cellules électrochimiques dont les géométries répondent aux contraintes fixées écoulement bidimensionnel ou axisymétrique tout en n'étant pas trop éloigné des réacteurs électrochimiques d'intérêt industriel: (i) cellule à plaques parallèles, à écoulement laminaire ou turbulent établi avec ou sans obstacle à l'écoulement et, (ii), cellule de déposition par jet immergé. La procédure de mesure des distributions de courant dans les cellules, au moyen de microélectrodes et d'un systeme d'acquisitions simultanées, a fait l'objet d'une recherche technologique importante. La comparaison, pas toujours aisée, des résultats théoriques et expérimentaux, fait l'objet d'une discussion approfondie
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Simões, Bianca Rebelo Lopes. "Estudo da oxidação de sulfetos pró-quirais com oxo diperoxo complexos de molibdênio (VI)." Universidade Federal de São Carlos, 2007. https://repositorio.ufscar.br/handle/ufscar/6394.
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Previous issue date: 2007-03-02Universidade Federal de Sao Carlos
This study describes the use of oxo diperoxo molybdenum (VI) complex using 2,2-bipyridine and N,N -dioxide-2,2 -bipyridine as ligands for the oxidation of a series of aliphatic and aromatic sulfides, ketosulfides, sulfinyl acids and olefinic sulfides. The preparation of these complexes, the reactivity and the chemeoselectivity in these sulfides oxidation reactions are discussed. This work also describes the enantioselectivity results obtained for the oxidation reaction of a series of alkyl aryl prochiral sulfides using the MoO5(N,N-DMLA) chiral complex. The enantioresolution of the series of alkyl aryl sulfoxides, using chiral polysaccharide stationary phases, in multimodal elution, is also demonstrated. The reactivity of MoO5(pyridine oxide)(H2O) complex, coated and uncoated to silica gel, for the series of alkyl aryl sulfides oxidation reactions were also thoroughly evaluated for comparison with the results obtained in previous studies with a different series of sulfide. The result obtained in this work discloses that, in these oxidation, reactions the reactivity depends, not only of the used complex, but also, of the nucleophilicity of the used sulfides. The preparation of MoO5(N,N-DMLA) chiral complex, by a variety of methods, and the characterization of the obtained products by infrared, ultraviolet 13C-NMR, microanalyses and optical activity are also reported.
Este trabalho descreve o uso de oxo diperoxo complexos de molibdênio (VI) contendo 2,2 -bipiridinas e N,N -dióxido-2,2, -bipiridinas, substituídas, como ligantes bidentados, para a oxidação de uma série de sulfetos pró-quirais funcionalizados, dentre eles, sulfetos alifáticos, aromáticos, cetossulfetos, sulfetos ácidos e olefínicos. O preparo dos complexos, sua reatividade e quimiosseletividade, em reações de oxidação de sulfetos são discutidos, levando em consideração estudos teóricos já desenvolvidos e os efeitos eletrônicos dos substituintes dos ligantes utilizados. O trabalho também reporta os resultados obtidos na oxidação enantiosseletiva de uma série de alquil aril sulfetos pró-quirais com o complexo quiral MoO5(N,N-DMLA), mostrando resultados promissores em relação aos excessos enantioméricos obtidos, assim como a influência estérica e eletrônica dos grupos substituintes dos sulfetos. A enantiorresolução da série de alquil aril sulfóxidos foi demonstrada, usando fase estacionária quiral de polissacarídeo, em eluição multimodal. A reatividade do complexo aquiral MoO5(óxido de piridina)(H2O), adsorvido à sílica e não adsorvido, também foi avaliada para a série de alquil aril sulfetos, e comparada com os resultados obtidos anteriormente para uma série de diferentes sulfetos. Os resultados obtidos neste trabalho mostraram que, na oxidação, a reatividade depende não só do complexo utilizado, mas também das características nucleofílicas de cada sulfeto. O preparo do complexo quiral MoO5(N,N-DMLA), através de diferentes métodos, e a caracterização do mesmo por infravermelho, ultravioleta-visível, 13C-RMN, análise elementar e atividade ótica também é reportado.
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Vichot, Laurent. "Spéciation du technétium en milieu chloro-sulfaté : contribution à l'étude des effets de la radiolyse gamma." Paris 11, 2001. http://www.theses.fr/2001PA112273.
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99Tc est l'un des plus importants produits de fission issu de l'industrie nucléaire. Malgré un rapport récent de l'OCDE, la chimie du technétium demeure très incomplète. Nous nous sommes intéréssés au comportement du Tc en milieu réducteur et en présence d'ions SO42- et Cl-. Des essais de préparation de composés sulfatés par réaction d'échange entre les ligands Cl- et SO42-, et par réduction de TcO4- en milieu sulfaté ont été réalisés. Dans le domaine de pH 0 à 4, une forme associée à un état réduit du technétium en solution existe indépendamment de la nature du milieu considéré. L'analyse de la structure a permis de démontrer que la formulation Tc(OH)2(SO4)22- avancée dans la littérature ne peut pas être retenue. La formule générale brute TcnIVOy(4n-2y)+ est proposée. L'étude XAS montre que le composé comporte 6 O compris entre 1,87 et 2,04 Å et 1 Tc à 2,51-2,54 Å autour de l'atome central de technétium. .99Tc is one of the most important fission products of the nuclear industry. In spite of recent revue on the technetium chemistry, numerous data are missing. Our interest was to shed light on the behavior of technetium in reducing media rich in SO42- et Cl- ion. We have attempted to prepare sulfate compounds of technetium using ligands exchange and reduction of TcO4- in sulfate media. For pH 0 to 4, one reduced species of technetium is formed in solution regardless to considered media. The analysis of the structure shows that the formula Tc(OH)2(SO4)22- given in the literature can not be retained. TcnIVOy(4n-2y)+ formula is proposed. XAS study shows thar within the complex formed the technetium is surround by 6 O at 1. 87 to 2. 04 Å and a first Tc neighbour at 2. 51-2. 54 Å. The position of the atoms of oxygen leads to the formation of such T(mu-O)2Tc bonds similar to those observed for the product obtained by the precipitation of Tc(IV) in basic media. In such way, TcnIVOy(4n-2y)+ can be considered as a precursor of TcO2. XH2O at pH superior at 3. .
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Duthil, Jean-Philippe. "Corrosion par piqûres du cuivre : synergie entre les ions chlorures, sulfates et nitrates." Toulouse, INPT, 1994. http://www.theses.fr/1994INPT024G.
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La corrosion par piqures du cuivre dans les eaux d'alimentation peut etre provoquee par diverses especes agressives, les ions chlorures, sulfates ou nitrates dont les teneurs peuvent etre variables selon le type d'eau dans laquelle l'attaque se produit. Afin de mieux comprendre le role de chacune de ces especes dans le mecanisme de la corrosion par piqures, des etudes de sensibilite a ce type d'attaque ont ete effectuees dans des solutions tampons de borate contenant soit l'un de ces ions soit deux de ces ions a des concentrations variables pour mettre en evidence les effets de synergie. La sensibilite a la corrosion par piqures a ete determinee par analyse statistique des temps d'amorcage des piqures sous polarisation potentiostatique. Cette sensibilite est quantifiee par la vitesse d'amorcage des piqures deduites des distributions des temps d'amorcage qui obeissent a une loi exponentielle. Les essais electrochimiques ont ete associes a l'etude de la morphologie des piqures et a l'analyse par spectroscopie esca et diffraction des rayons x des films passifs et des produits de corrosion. Les resultats obtenus ont permis de montrer que lorsqu'une espece agre ssive donnee est responsable de la germination des piqures, les autres ions modifient le comportement du cuivre soit en accelerant soit en inhibant partiellement l'apparition des piqures selon leur concentration dans la solution
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Jhanwar, Shalu 1986. "Computational analysis of epigenomic variability and its effect on regulatory activity." Doctoral thesis, Universitat Pompeu Fabra, 2017. http://hdl.handle.net/10803/580601.
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Epigenetics provides a plausible link between the environment and changes in gene
expression that might contribute to disease phenotypes. The main goal of the thesis is
to study epigenomic variability and their effect on the regulatory activity underlying
chromatin dynamics. With an ultimate aim to identify regulatory variants driving
cancer as well as disease specific epigenomic patterns in neurological diseases, the
thesis deals with the development and subsequent implementation of a novel
supervised machine-learning based enhancer predictor (GEP). Further, to address the
role of DNA methylation during development of two distinct larval morphs from a
single egg in a parasitic polyembryonic wasp, we have developed a novel
computational method (dMeth-X) that identifies putative differentially methylated
genes responsible for morphological and behavioral differences between the larval
forms. Additionally, the thesis focuses on the study of the effect of external factors on
the epigenomic variability on the mouse brain cortex. Overall, we believe that my
doctoral thesis is a successful endeavor to study the epigenetic variability and
regulatory activity using next-generation sequencing approaches.La epigenética proporciona un enlace plausible entre el medio ambiente y los cambios en la expresión de genes que podrían contribuir a fenotipo de las enfermedades. El objetivo principal de la tesis es el estudio de la variabilidad epigenómica y su efecto sobre la actividad reguladora subyacente a la dinámica de la cromatina. Con un objetivo último de identificar variantes de regulación que contribuyen al cáncer, así como patrones epigenómicos específicos en enfermedades neurológicas, las tesis se enfoca en el desarrollo y posterior aplicación de un nuevo método supervisado para predecir potenciadores basado en aprendizaje automático (GEP). Además, para abordar el papel de la metilación del ADN en la configuración de dos formas larvarias distintas de un solo huevo en una avispa poliembriónica parasitaria, hemos desarrollado un nuevo método computacional (dMeth-X) para identificar los genes diferencialmente metilados que podrían contribuir distinguiendo formas larvarias contrastantes. Adicionalmente, la tesis incorporó el estudio del efecto de factores externos sobre la variabilidad epigenómica de la corteza del cerebro de ratón. En general, creemos que mi tesis doctoral es un esfuerzo exitoso para estudiar la variabilidad epigenética y la actividad reguladora utilizando enfoques de secuenciación de próxima generación.
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Tasso, Carlos Roberto Batista. "A busca de um método espectrofotométrico com complexos de rutênio para estimação quantitativa da 1,3,5-triazina-1,3,5-(2H,4H,6H)-trietanol residual usada para eliminação do H2S presente no refino do petróleo." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/75/75135/tde-09082016-141934/.
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Nesse trabalho foi estudada uma técnica para a detecção de OHTC na água salina. Descobriu-se que certos complexos de rutênio em determinados valores de pH reagem com a molécula de OHTC e isto é detectável por espectrofotometria UV-Vis. Foram estudados os complexos fac-[RuCl2(S-DMSO)3(O-DMSO)] (complexo 1), {[(DMSO)2H][trans-RuCl4(DMSO)2]} (complexo 2) e cis-[RuCl2(bpy)2].2H2O (complexo 3). O complexo 1 possui um dos ligante (O-DMSO) que pode ser substituído pelo OHTC. Já o complexo 2 possui um dos ligantes (S-DMSO) na posição trans um ao outro, e o complexo 3 possui os 2 íons Cl- para tal finalidade. Determinou-se que o complexo 1 é viável, mesmo em presença de sais presentes na água do mar. Assim a reação foi realizada em função do tempo, variação do pH, temperatura e concentração de OHTC. Nos outros dois complexos os estudos foram realizados sem a variação da temperatura e concentração de OHTC.p>In this work we studied a technique for detection of OHTC in water. It was discovered that complexes involving ruthenium, on determined pH values, react with the OHTC molecule and this is detectable by UV-VIS spectroscopy. The complexes fac-[RuCl2(S-dmso)3(O-dmso)] (complex 1), {[(DMSO)2H][trans-Ru(DMSO)2Cl4]} (complex 2), and cis-[RuCl2(bpy)2].2H2O (complex 3) were studied. The complex 1 present one position ( O - DMSO) which can be substituted by the OHTC. Additionally, the complex 2 present two ligands ( S- DMSO) trans between each other, and the complex 3 present two chloride ions for the same porpose of complex 1 respectively. It was determined that the complex 1 was able to react with OHTC even in presence of the salts present in sea water. Thereby, the reaction involving complex 1 and OHTC was monitored in function of the time, pH, temperature, and finally concentration of OHTC. On the other two complexes, the reaction was studied without variation of temperature and concentration of OHTC.
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Vita, Nicolas. "Protection contre le stress oxydant de la pyruvate : ferrédoxine oxydoréductase des Desulfovibrio, une enzyme cIef du métabolisme anaérobie." Aix-Marseille 1, 2009. http://www.theses.fr/2009AIX11079.
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La Pyruvate: Ferrédoxine oxydoréductase (PFOR) est une enzyme clef des métabolismes anaérobies qui catalyse l'oxydation réversible du pyruvate en acétyl-coenzymeA et CO2. Généralement, cette enzyme présente une grande sensibilité à l'oxygène induite par la présence de centres [4Fe-4S]2+/1+ dans la protéine. La caractérisation extensive de la PFOR de Desulfovibrio africanus (Da) a révélé une stabilité inédite de cette protéine en présence d'air. Mon travail a permis de spécifier le mécanisme de protection de la PFOR de Da à l'aide d'une étude de mutagenèse dirigée associée à des expériences in vivo. Le mécanisme est dépendant d'un « switch rédox » de deux cystéines qui permettrait de positionner une méthionine dans l'environnement immédiat d'un centre [4Fe-4S] afin de le protéger des dommages oxydatifs. Les analyses in vivo ont démontré que, dans les cellules, la PFOR de plusieurs Desulfovibrio, est efficacement protégée contre un stress oxydant. De plus, la forme stable mais inactive de l'enzyme qui est formée au cours de l'oxydation peut être réactivée par un retour en conditions réductrices. Cette réactivation correspond au clivage du pont di sulfure présent dans l'enzyme oxydée. Afin de caractériser les partenaires moléculaires catalysant, in vivo, ce clivage, nous nous sommes intéressés aux systèmes thiol-rédox des Desulfovibrio. Dans ce contexte, nous avons initié l'étude des thiorédoxines et des thiorédoxine réductases de Desulfovibrio vulgaris Hildenborough (DvH). En parallèle, nous avons étudié le rôle physiologique de la PFOR chez DvH, en mettant en œuvre une stratégie de délétion du gène porR. A l'heure actuelle, nous n'avons pas obtenu le mutantporK. Cependant nous avons démontré que ce gène appartenait à. Un opéron codant pour plusieurs protéines reliées fonctionnellement. Ainsi, la PFOR ferait parti d'un super-complexe impliqué dans l'oxydation du substrat énergétique et la production d'ATPThe Pyruvate-Ferredoxin Oxidoreductase (PFOR) is a key enzyme of anaerobic metabolisms that catalyses the reversible oxidation of pyruvate in acetyl-coenzymeA and CO2. Usually, this enzyme is highly sensitive to oxygen, because of the presence of iron- sul fur clusters. However, extensive studies of Desulfovibrio africanus (Da) PFOR pointed out a surprising stability of this protein when exposed to air. My PhD work wanted to get a better understanding of the protective mechanism of Da PFOR, using a directed-mutagenesis. Approach coupled to in vivo assays. We characterized a redox switch mechanism involving two cysteines that would direct the positioning of a methionine near one of the iron-sulfur clusters, thus protecting it from oxidative damages. In vivo analysis showed that PFORs from several Desulfovibrio species, are efficiently protected against oxidative stress. This redox-switch leads to a stable but inactive form of the enzyme under oxidative conditions that can be reactivated, in vivo, when conditions are shifted back to reducing ones. This reactivation requires the reduction of the disulfide bond of the oxidized enzyme. In order to identify the molecular partners that catalyse this reduction in vivo, we have started to study the thioredoxins and thioredoxin reductases of Desulfovibrio vulgaris Hildenborough (DvH). We also studied the PFOR physiological role in DvH, using a gene deletion approach , although until now, we haven't been able to obtain the porK mutant. But we have shown that this gene belongs to an operon coding for several proteins functionally linked. Therefore, the PFOR might be part of a supra-complex involved in the oxidation orthe energetic substrate and ATP production
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Qafsaoui, Wafaa. "Sensibilité du cuivre pur ou faiblement allié à la germination des piqûres dans des solutions tampons contenant des ions chlorures, sulfates ou nitrates." Toulouse, INPT, 1992. http://www.theses.fr/1992INPT054G.
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La sensibilite a la corrosion par piqures du cuivre pur ou faiblement allie dans des solutions tampons a ete determinee par analyse statistique des temps d'induction des piqures. Cette sensibilite est quantifiee par la vitesse de germination des piqures deduite des distributions des temps d'induction qui obeissent a une loi exponentielle. Quand le film passif n'a pas le temps d'evoluer pendant les essais (cas ou les temps d'induction sont courts), la resistance a la corrosion par piqures ne varie pas de facon significative avec le temps et la vitesse de germination des piqures est constante. Par contre, lorsque les temps d'induction sont eleves, la vitesse de germination des piqures decroit avec le temps. Cette decroissance a pu etre modelisee a partir des observations faites sur l'influence de la duree de prepolarisation. L'evolution du film passif avec le temps en presence de chlorures est plus favorable vis-a-vis de la resistance a la corrosion par piqures que celle se produisant en leur absence. La corrosion par piqures se manifeste aussi bien en presence de chlorure que de sulfate ou de nitrate avec les memes lois de distributions des temps d'induction. L'agressivite de ces ions augmente dans l'ordre: chlorure, sulfate, nitrate. L'influence de divers parametres (conditions de polarisation, composition des materiaux, teneur en ions agressifs) sur la vitesse de germination des piqures a ete mise en evidence
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Costalat, Marie. "Structure et mécanisme d’élaboration de biomatériaux par complexation contrôlée de polysaccharides." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10265/document.
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Nos travaux ont porté sur le développement d'une méthode contrôlée de complexation de polyélectrolytes. La complexation est un processus spontané, sous contrôle cinétique et irréversible dans le cas de polysaccharides tels que le chitosane et les polysulfates, essentiellement le sulfate de dextrane ou l'héparine. Une conséquence de ce contrôle cinétique est que l'obtention d'objets de taille colloïdale requiert de travailler à fortes dilutions. De plus, les nanovecteurs obtenus ne sont pas toujours compatibles avec des conditions d'utilisation dans des milieux physiologiques. Le contrôle de l'association de polysaccharides se fait par écrantage des interactions électrostatiques attractives en présence de chlorure de sodium à la concentration au moins égale à 2 mol.L-1. L'élimination du sel par dialyse induit la formation d'hydrogels dont les caractéristiques et les propriétés dépendent principalement du rapport de charges n+/n- et de la cinétique d'élimination du sel. Ainsi, l'on peut former des hydrogels massifs ou des systèmes dispersés à des concentrations en polymères jusqu'à 30 fois plus élevées que par les méthodes sous contrôle cinétique. De plus, cette technologie permet l'encapsulation des principes actifs dans les particules qui peuvent aussi être fonctionnalisées par des biomolécules d'adressage. Le résultat majeur de ce travail réside en la maîtrise des associations entre polysaccharides de charges opposées, permettant d'obtenir des systèmes colloïdaux et massifs à fort potentiels d'applications biomédicalesOur work dealt with the development of a controlled method of polyelectrolyte complexation. The complexation is a spontaneous process, under kinetic control and irreversible in the case of polysaccharides such as the chitosan and polysulfates, essentially dextran sulfate or heparin. A consequence of this kinetic control is the requirement to work at high dilution to obtain objects of colloidal size. Moreover, the obtained nanovectors were not always adapted for use in physiological media. The control of the association of polysaccharides was achieved by screening the attractive electrostatic interactions in the presence of sodium chloride at concentration at least equal to 2 mol. L-1. Removal of salt by dialysis resulted in the formation of hydrogels, whose characteristics and properties depended mainly on the charge ratio n +/ n- and the kinetics of the salt elimination. Thus, massive or dispersed hydrogels were formed at polymer concentrations up to 30 times higher than by the methods under kinetic control. Furthermore, this technology allowed the encapsulation of active ingredients in the particles that could also be functionalized with biomolecules for targeting. The major result of this work was the control over the associations between oppositely charged polysaccharides which provided colloidal and massive systems of high potentialities in biomedical applications
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CÃndido, Manuela Chaves Loureiro. "Study of the Reactivity of complex ions cis-[Ru (bpy)2(L) (NO)]n+ where L = imidazole, 1-metilimidazole, thiourea and sulfite." Universidade Federal do CearÃ, 2011. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=7208.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoWe carried out studies of chemical reactivity, electrochemistry and photochemistry of complexes cis-[Ru(bpy)2(L)(NO)](PF6)n, where L = imidazole, 1-methylimidazole, thiourea and sulfite. Were chosen, therefore, two ligands being donors and two with ligands that act as -recipient and the results indicated that the nature and strength of these ligands directly influence the strength of the back donation between the metal center and coordinated nitric oxide. The infrared spectra showed a characteristic frequency of nitric oxide coordinated as NO+, and there was variation in the observed value of frequency of NO stretching, dependant of the auxiliary ligand. The results indicate that the backbonding between Ru and NO+ is stronger in the complex featuring the sulfite ligand in the coordination sphere, that complex having a minimum value to that specific stretching frequency, when compared to the other complexes. The experimental data corroborate with the Lever parameter values for the ligands, indicating the contribution of them to the electron density of the metal. The cyclic voltammetry performed in aqueous media indicate that the reduction of NO+ species to NO0 is facilitated with the increase of electron density donation from auxiliary ligands to the metallic center. And the differential pulse voltammetry indicates the possibility of the formation of aqueous-complex from a chemical reaction, after coordinated NO+ reduction. This work have shown that the photochemical release of nitric oxide from the light stimulation of complex solutions is consistent, even being possible to determine the species formed as a product of the photolysis and subsequent calculations of quantum yield of NO0 realese. Quantification of nitric oxide release was performed indirectly, using the technique of square wave voltammetry, which was efficient for the purpose. It was also used a selective electrode for free NO0 molecule, confirming that irradiation of NO+ compounds solutions actually cause the release of coordinated nitric oxide (NO+) to its active form in biological environment.
Neste trabalho foram realizados estudos de reatividade quÃmica, eletroquÃmica e fotoquÃmica dos complexos cis-[Ru(bpy)2(L)(NO)](PF6)n, onde L= imidazol, 1-metilimidazol, tiourÃia e sulfito. Foram escolhidos, portanto, dois ligantes auxiliares com caracterÃsticas doadoras e dois com caracterÃsticas receptoras e os resultados obtidos indicaram que a natureza e forÃa destes ligantes influenciam diretamente na retrodoaÃÃo existente entre o centro metÃlico e o Ãxido nÃtrico coordenado. Os espectros de infravermelho apresentaram freqÃÃncia caracterÃstica de Ãxido nÃtrico coordenado na forma NO+, sendo que houve variaÃÃo dos valores conforme a variaÃÃo do ligante auxiliar. Os resultados indicam que a interaÃÃo existente (retrodoaÃÃo) entre o Ru e o NO à mais forte para o complexo que apresenta o ligante sulfito na esfera de coordenaÃÃo, por apresentar um menor valor de freqÃÃncia de estiramento quando comparado aos demais complexos. Os dados experimentais corroboram com os valores do parÃmetro de Lever encontrados para os ligantes, que indicam a contribuiÃÃo dos mesmos para a densidade eletrÃnica do metal. Os ciclovoltamogramas, realizados em meio aquoso, indicam que a reduÃÃo da espÃcie NO+ a NO0 à facilitada quanto maior for a doaÃÃo de densidade eletrÃnica do ligante âLâ para o centro metÃlico. E a voltametria de pulso diferencial indica a possibilidade da formaÃÃo do aquo-complexo a partir de uma reaÃÃo quÃmica apÃs a reduÃÃo de Ãxido nÃtrico. Os estudos fotoquÃmicos mostraram que a liberaÃÃo de Ãxido nÃtrico a partir do estÃmulo luminoso de soluÃÃes dos complexos à consistente, sendo possÃvel inclusive a determinaÃÃo da espÃcie formada como produto da fotÃlise e posteriores cÃlculos de rendimento quÃntico da formaÃÃo das mesmas. A quantificaÃÃo da liberaÃÃo de Ãxido nÃtrico foi realizada de maneira indireta, utilizando a tÃcnica de voltametria de onda quadrada, que se mostrou eficiente para o objetivo. E foi utilizado tambÃm um eletrodo seletivo para a molÃcula de NO0 livre, confirmando que a irradiaÃÃo das soluÃÃes realmente leva a liberaÃÃo do Ãxido nÃtrico coordenado na sua forma ativa em meio biolÃgico.
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Zaze, Cesar Aurélio [UNESP]. "Análise da variação da posição relativa dos dentes artificiais no arco dental em função do processamento de próteses totais mandibulares mensurada por computação gráfica." Universidade Estadual Paulista (UNESP), 2005. http://hdl.handle.net/11449/97381.
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Este trabalho foi idealizado com o intuito de contribuir para os estudos pertinentes à área da prótese total, e teve como objetivo analisar a alteração da posição relativa dos dentes artificiais em razão do processamento de 40 próteses totais inferiores, obtidas por uma matriz de silicone pré-moldada. Na metodologia, as próteses foram divididas em quatro grupos de 10, que receberam os seguintes tratamentos: Grupo 1 - inclusão em muflas metálicas com muralha de gesso pedra tipo III e polimerização em banho de água quente; Grupo 2 - inclusão em muflas de fibra de vidro com muralha de gesso pedra tipo III e polimerização em microondas; Grupo 3 - inclusão em muflas metálicas com muralha de silicone e polimerização em banho de água quente e Grupo 4 - inclusão em muflas de fibra de vidro com muralha de silicone e polimerização em microondas. Como conclusões, os resultados demonstraram que houve alteração na posição dos dentes artificiais em todas as técnicas de processamento, com o grupo 3 apresentando os melhores resultados seguido dos grupos 4, 2 e 1.
The purpose of this study is to analyze the change in denture tooth position in the fabrication of complete mandibular dentures after different processing techniques. A total of 40 mandibular complete dentures, obtained by a premolded matrix of silicon, were fabricated. There were a total of four groups of complete mandibular dentures. Each group consisted of 10 complete mandibular dentures which were fabricated in the following manner: Group 1 - were processed in a metallic flask using stone plaster type III and polymerized in hot water; Group 2 - were processed in a fiberglass flask using stone plaster type III and polymerized in a microwave; Group 3 - were processed in a metallic flask using silicon and stone plaster type III and polymerized in hot water; Group 4 - were processed in a fiberglass flask using silicon and stone plaster type III and polymerized in a microwave. In conclusion, the results demonstrated that there were alterations in tooth position in all processing techniques. However, Group 3 presented with the least amount of change in tooth positon, followed by Group 4, then Group 2, and finally Group 1 with the most amount of change in tooth position.
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Espinosa, Andrés Villaseñor. "Tentativa de obtenção de sulfato de D-glicosamina a partir de mostos fermentados e síntese de complexos de ouro (I) com ligantes derivados de D-glicose." Universidade Federal de Juiz de Fora (UFJF), 2018. https://repositorio.ufjf.br/jspui/handle/ufjf/6788.
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As doenças reumáticas são até hoje uma das principais causas de incapacidade física em diversos estratos populacionais. As principais doenças reumáticas (em termos de número de incidências) são a osteoartrite (também conhecida como artrose) e a artrite reumatoide (AR), as quais atingem milhões de pessoas no mundo e nenhuma delas tem cura conhecida. Diversos tipos de compostos, como por exemplo, D-glicosamina e sais de ouro (I) e (III), devido à sua potencial aplicação como fármacos no tratamento das doenças reumáticas, são alvo de muitos grupos de pesquisa na area da química medicinal. Neste trabalho foi purificado um complexo quitina-glicano (CQG) a partir de mostos fermentados de cerveja, o qual foi submetido a diversos processos de hidrólise ácida e enzimática. Foi isolado D-glicose em grande rendimento, porém não foi possível obter D-glicosamina, nem outros sacarídeos. Também foram sintetizados 4 complexos de ouro (I) os quais foram produzidos reagindo-se os sais de ouro Au[PEt3]Cl e Au[PPh3]Cl com compostos derivados de D-gliconolactona. Estes foram sintetizados submetendo-se a D-gliconolactona a reações de formação de cetais e o grupo hidrazida, para depois serem ciclizados com CS2 para formar os derivados de oxadiazolidina, formando assim os ligantes desejados. Os ligantes foram finalmente reagidos com duas variedades de sais de ouro contendo grupo fosfina para a formação do complexo de ouro (I) correspondente. Os complexos de ouro (I) e os ligantes usados estão sendo avaliados biologicamente quanto à sua potencial aplicação no tratamento de artrose e artrite reumatoide, assim como no tratamento de leishmania.
Rheumatic diseases are nowadays one of the most recurring causes of physical disability among all sectors of society. The most common rheumatic diseases (in terms of incidence rates) are osteoarthritis (also known as arthrosis) and rheumatoid arthritis, which both affect world's population by millions and none of them have a known cure. Various types of chemical compounds, such as gold (I) and (III) salts and D-glucosamine, are widely studied by various research groups in the field of medicinal chemistry because of their potential application as treatment drugs for rheumatic diseases. In this work, a quitin-glucan complex was obtained from brewer's spent yeast, which was submitted to subsequent stages of acid and enzymatic hydrolysis. High quantities of D-glucose were harvested from these processes, but no measurable amount of D-glucosamine or any other saccharides were found. Also, four gold (I) complexes were produced by reacting Au[PEt3]Cl and Au[PPh3]Cl gold salts with D-gluconolactone-derived compounds. These were synthesized by working up D-gluconolactone through ketal and hidrazide formation followed by oxadiazolidine cyclization with CS2 to achieve the desired ligands. These ligands were subsequently treated with two different phosphine-containing gold salt moieties to obtain the corresponding gold (I) complexes. The aforementioned complexes and their corresponding ligands are being biologically tested for potential rheumatoid arthritis and ostheoarthrosis treatment, as well as leishmania treatment.
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Apgar, Gary Allen. "Evaluation of a copper lysine complex and copper sulfate in weanling and finishing pigs, and the effect of copper supplementation on circulating growth hormone and IGF-1 levels." Diss., Virginia Tech, 1994. http://hdl.handle.net/10919/40203.
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The objectives of this research were 1) to evaluate CuS0₄ and a CU lysine complex (CuLys) as growth promotants for weanling pigs, 2) to assess the effects of feeding growth stimulating levels of Cu from both sources on dry matter digestibility (DMO) and mineral balance of finishing pigs, and 3) to examine the effect of feeding elevated CU on serum growth hormone and IGF-1 levels. Two trials (176 pigs) were conducted in which pigs were fed 0, 100, 150, or 200 mg/kg Cu from CUS0₄ or CuLys. Elevated Cu increased daily gain and feed intake linearly, with no difference between the sources. Dietary CU linearly increased liver, kidney (P < .001), and brain (P < .05) Cu stores. In the liver, the linear response between the sources was different (P < .001); pigs fed 200 mg/kg Cu from CuLys had the highest CU concentration. Serum CU increased linearly with no difference between the two sources. Serum mitogenic activity increased linearly during wk 1 to 2 and 1 to 5 (P < .05), with no difference between the two sources. Twenty-four barrows were used to examine the effect of Cu additions from both Cu sources on digestibility and mineral balance. Pigs fed Cu from CuLys tended to have greater DMD when compared with controls (P < .10), but percentage of Cu absorbed was not different among the treatments. Pigs fed Cu from both sources absorbed more eu than controls (P < .01), with no difference between sources. Pigs fed CuS0₄ (P < .027) and CuLys (P < .101) absorbed more Fe than controls but Zn balance was not affected. Twelve pigs were cannulated after 7 wk of growth to quantify the effect of elevated dietary Cu on circulating growth hormone and IGF-1 levels. Growth performance was not improved by added Cu, but efficiency of gain was greater for pigs fed Cu when compared with controls (P < .101). Baseline growth hormone secretion was greater in pigs fed Cu (P < .06) for three of four days; however, average concentrations were not affected by diet. Concentrations of IGF-1 were higher in control pigs (P < .05).Ph. D.
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Bowden, Jennifer A. "Relative Absorption of Iron and Magnesium from Sulfate Salts, Amino Acid Chelates Complexed and/or Mixed with Vegetables, and Taste-Free Supplements." DigitalCommons@USU, 1997. https://digitalcommons.usu.edu/etd/5435.
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Common methods for determining mineral absorption by the body are invasive and frequently utilize radioisotopes. In experiment one. rats were given a dose of radiolabeled ferrous sulfate. Relative absorption was estimated by changes in serum iron and by appearance of the radiotracer in the serum. There were no differences in relative absorption determined by the methods, although the low overall absorptions by the iron-replete rats may have decreased the sensitivity.
In experiments two and three. iron and magnesium supplements were given orally to 12 women age 19-25. Each subject received iron and magnesium supplements once each week for 5 weeks. Blood samples were taken via venous catheter every 30 minutes for 2 hours and 30 minutes following dosing, and a urine sample was taken following the collection time period. Samples were analyzed for serum iron, serum magnesium, hematocrit, ferritin, urinary magnesium, and urinary creatinine. The increase in serum iron was evaluated from both the peak increase in serum iron and from the integrated increase in serum iron over the blood collection time. The data for each supplement were compared by analysis of variance. For the iron supplements. the taste-free iron supplement increased serum iron less than either the Ferrochel or the ferrous sulfate supplements. When the iron absorption was then compared to ferritin stores (low, medium, and high), the relative absorption of Ferrochel was higher in the low ferritin range (0-15 ng/ml) than in the upper ranges (P=.00l for peak and P=.0002 for area). Relative absorption from Ferrochel iron was also higher than the other supplements for subjects with low ferritin stores.
Neither serum nor urinary magnesium values differed significantly among the three compounds examined. Serum magnesium values are stable in healthy individuals, and the urinary magnesium data were not evaluated over 24 h as in typical magnesium load tests.
In summary, both the ferrous sulfate and Ferrochel supplements were absorbed more efficiently than the taste-free iron supplement. The Ferrochel was also absorbed more efficiently in individuals with low iron stores, demonstrating better regulation by the body than with the other supplements examined.
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Bonvoisin, Jacques. "Interaction d'échange dans des complexes polynucléaires de fer et de manganèse d'origine biologique ou synthétique : étude expérimentale et théorique." Paris 11, 1989. http://www.theses.fr/1989PA112133.
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Ce travail comporte trois parties. La première concerne l'étude magnétique de sites actifs de métallobiomolécules en utilisant un susceptomètre à SQUID. De par sa haute sensibilité, cet instrument permet de mesurer le signal paramagnétique de métalloprotéines en solution. Nous avons développé une méthodologie de ces mesures. Nous avons appliqué cette technique à des protéines fer-soufre comme la protéine Sulfite Réductase ou la protéine Ferrédoxine II et des protéines au fer à pont oxo comme la protéine Utéroferrine. Nous confrontons nos résultats à ceux obtenus par d'autres méthodes. Dans la deuxième partie de ce travail, nous exposons les propriétés magnétiques de complexes homo et hétérobinucléaires présentant le motif suivant [M(III)(μ - O)(μ -CH3CO2)2M'(III)]2+ avec M,M'=Fe,Fe; Fe,Mn ; Fe,Cr; Mn,Mn; V,V. Nous envisageons ensuite la relation entre les phénomènes d'échange et la liaison métal-métal en nous appuyant sur notre étude expérimentale d'un composé dinucléaire du Mn(IV) où les ions sont pontés par trois ligands μ-oxo. Enfin, dans la dernière partie, nous examinons la spectroscopie de systèmes polynucléaires à valence mixte au Mn(III) et Mn(IV) et élaborons différents modèles pour interpréter le spectre RPE multiligne observé pour l'état S2 du site de dégagement d'oxygène des plantesThis work is constituted of three parts. The first part involves magnetization studies of biomolecule metallic active sites using a SQUID susceptometer. Due to the high sensitivity of those new susceptometer, the paramagnetic signal of metallic centers of metalloproteins in solution can now be measured accurately. We developed new methods to achieve those measurements. We applied this technique to iron-sulfur proteins like Sulfite Reductase or Ferredoxine II and proteins containing two iron atoms bridged by an oxo group like Uteroferrin. We compare our results with those obtained by other methods. In the second part of this work, we present magnetic properties of homo and heterodinuclear compounds exhibiting the core [M(III)(μ - O)(μ -CH3CO2)2M'(III)]2+with M,M' = Fe,Fe; Fe,Mn; Fe,Cr; Mn,Mn; V,V. Then, we explore the relationship between exchange phenomena and metalmetal bonding using our experimental study of a Mn(IV) dinuclear compound where the two manganese atoms are bridged by three oxo groups. In the last part, we examine EPR spectroscopy of polynuclear Mn(III) and Mn(IV) compounds and build up various madel in order to interpret the multiline EPR spectra of the 82 state of the Oxygen Evolving Center of the Photosystem II of plants
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Hanauer, Kristina [Verfasser]. "Ferrocene as redox-functional group in N,N'-disubstituted (thio)ureas and sulfite oxidase mimicking molybdenum complexes / Kristina Hanauer." Mainz : Universitätsbibliothek Mainz, 2018. http://d-nb.info/1164255835/34.
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Hassan, Abduljabbar. "Contribution à la synthèse et à l'analyse structurale des complexes perchlorato : comportement du trioxyde de chlore vis-à-vis de chlorures, de nitrates, de sulfates et d'un carbonate." Montpellier 2, 1986. http://www.theses.fr/1986MON20116.
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On confirme les fonctions perchloratante et dishydratante de cl::(2)o::(6) et sa fonction de catalyseur de polymerisation. Etude structurale des complexes a structure lamellaire co(clo::(4))::(2), cd(clo::(4))::(2) ou de complexes a chaine anionique. En general le groupe clo::(4) est bidente ou tridente
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Knapp, Quintin Wayne. "The spectroscopic analysis of di-copper helicates as receptors for encapsulating anions : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Chemistry at Massey University, Palmerston North, New Zealand." Massey University, 2009. http://hdl.handle.net/10179/915.
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The application of neutral dicopper helicates to the encapsulation of a number of anions was investigated. Two dicopper salen derived helicates were studied which contained phenolic and either iminophenyl (1) or oxime (2) donor groups. UV-visible spectroscopy was used to determine the binding stoichiometry and formation constants of the anion complexes. Complex binding was supported by electrospray ionisation mass spectrometry. Receptor 1 possessed a remarkable selectivity for sulfate in isopropanol (IPA) for which a log K value of 5.07 ± 0.24 was obtained. Receptor 2 bound all anions studied more strongly than 1. Crystal structural data supports the proposition that there is a steric barrier to contraction of 1 from the bulky iminophenyl groups. Receptor 2 was not restricted by the small oxime moieties allowing for optimum copper-anion interactions.
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Boumezioud, Mohamed. "Complexion de métaux de transition par des hydroxyquinolines en milieux homogènes et microhétérogènes : Influence de l'hydrophobie du ligand sur la cinétique réactionnelle dans des phases microémulsions." Nancy 1, 1987. http://www.theses.fr/1987NAN10276.
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Étude de la complexation de métaux de transition (nickel, cobalt) par des ligands bidentes du type hydroxy-8 quinoline dans des milieux homogènes (eau et méthanol) et des milieux microhétérogènes (solution micellaire, microémulsion), tant du point de vue thermodynamique que cinétique