Download or read book REACTIVITE CHIMIQUE DES COMPLEXES DINUCLEAIRES DE FER III A PONT OXO written by CAROLE.. DUBOC TOLA and published by . This book was released on 1998 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: MODELISER LE SITE ACTIF D'UNE METALLOENZYME EST UNE APPROCHE INDISPENSABLE A LA CARACTERISATION PRECISE DE SON SITE METALLIQUE ET A LA COMPREHENSION DE SON MECANISME D'ACTION. AU LABORATOIRE, NOUS NOUS SOMMES PLUS PARTICULIEREMENT INTERESSES A DEUX ENZYMES LA METHANE MONOOXYGENASE (MMO) ET LA PHOSPHATASE ACIDE POURPRE (PAP) ISSUES DE LA CLASSE DES PROTEINES A FER OXO, ENZYMES CONTENANT TOUTES AU SEIN DE LEUR SITE ACTIF UN SYSTEME DINUCLEAIRE DE FER (III) PONTE PAR UN OXYGENE. LEURS ACTIVITES CATALYTIQUES, OXYDATION D'ALCANES POUR LA MMO ET HYDROLYSE DE PHOSPHOESTERS POUR LA PAP, ONT ETE REPRODUITES A L'AIDE DE NOUVEAUX COMPLEXES DINUCLEAIRES DE FER (III) A PONT OXO. DANS LE CAS DE LA CATALYSE D'OXYDATION D'ALCANES, NOTRE PREMIER OBJECTIF A ETE D'OPTIMISER LES PREMIERS COMPLEXES SYNTHETISES AU LABORATOIRE. POUR SE FAIRE, LA STABILITE DES COMPLEXES A ETE AMELIOREE ET DES CONDITIONS D'OXYDATION EFFICACES ONT ETE MISES AU POINT EN UTILISANT LE PEROXYDE D'HYDROGENE COMME OXYDANT. QUANT A LEUR MECANISME D'ACTION, L'INTRODUCTION D'ELEMENTS DE CHIRALITE AU SEIN DES COMPLEXES A PERMIS D'EFFECTUER DES HYDROXYLATIONS ENANTIOSELECTIVES, DEMONTRANT AINSI QUE LA REACTION EST CENTREE SUR LE METAL. L'ENSEMBLE DES RESULTATS AINSI QUE LA CARACTERISATION D'UN INTERMEDIAIRE, UN COMPLEXE DINUCLEAIRE DE FER (III) -OXO -PEROXO A PERMIS DE PROPOSER UN MECANISME D'ACTION QUI EST PROCHE DE CELUI PROPOSE POUR LA MMO. CES COMPLEXES OPTIQUEMENT ACTIFS SE SONT AUSSI REVELES ETRE DE BONS CATALYSEURS D'OXYDATION DE SULFURES. ILS SONT CHIMIOSPECIFIQUES PUISQUE SEUL LE SULFOXYDE EST FORME ET LES REACTIONS SONT ENANTIOSELECTIVES. LE MECANISME D'ACTION A ETE ENTIEREMENT ELUCIDE GRACE A DES ETUDES CINETIQUES ALLIEES A DES ETUDES SPECTROSCOPIQUES. POUR LA PREMIERE FOIS, LA REACTIVITE D'UN SYSTEME PEROXO FERRIQUE A ETE MISE EN EVIDENCE. ENFIN, NOUS AVONS ETUDIE LES PROPRIETES ACIDO-BASIQUES D'UN DE CES COMPLEXES DANS L'EAU. CECI A CONDUIT A LA SYNTHESE DU PREMIER COMPLEXE DINUCLEAIRE DE FER (III) A PONT -OXO POSSEDANT DEUX LIGANDS HYDROXO STABLES AUSSI BIEN A L'ETAT SOLIDE QU'EN SOLUTION. SON ACIDE CONJUGUE S'EST REVELE EFFICACE EN HYDROLYSE DE PHOSPHODIESTERS. L'ETUDE DU MECANISME A MIS EN EVIDENCE LE ROLE ESSENTIEL D'UN LIGAND HYDROXO ET L'IMPORTANCE DE LA STRUCTURE DINUCLEAIRE DU SYSTEME QUI PERMET UNE SYNERGIE ENTRE LES DEUX SITES METALLIQUES. CE SYSTEME CHIMIQUE REPRESENTE LE PREMIER MODELE A LA FOIS STRUCTURAL ET FONCTIONNEL DE L'ENZYME ET SA REACTIVITE VALIDE LE MECANISME D'ACTION PROPOSE POUR LA PAP.

Download or read book Etude du mecanisme de l hydrolyse des hydroxocomplexes de fe ii written by Mario Levental and published by . This book was released on 1977 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book COMPLEXATION DU FER PAR DES LIGANDS TRIPODES A BASE DE SOUS UNITES 8 HYDROXYQUINOLEINE ET 2 2 DIHYDROXYBIPHENYLE ASPECTS THERMODYNAMIQUES ET CINETIQUES written by HAKIM.. BOUKHALFA and published by . This book was released on 1996 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: CE TRAVAIL CONCERNE DES ETUDES THERMODYNAMIQUES ET CINETIQUES DE LA COMPLEXATION DU FER(III) PAR DES LIGANDS POSSEDANT DES SITES DE COORDINATION DE TYPE 8-HYDROXYQUINOLEINE ET 2,2'-DIHYDROXYBIPHENYLE. LA PREMIERE PARTIE A CONCERNE L'ETUDE DES COMPLEXES FERRIQUES DES LIGANDS 8-HQ (OXINE), 5-SO#3#--8-HQ (SULFOXINE) ET 5-F-8-HQ (FLUOROOXINE). LES RESULTATS METTENT EN EVIDENCE L'INFLUENCE DES PROPRIETES ELECTRONIQUES DES SITES DE COORDINATION SUR LA STABILITE DES COMPLEXES. QUAND LA COORDINATION DU FER PAR LE LIGAND N'EST PAS COMPLETE, DES HYDROXO COMPLEXES SONT FORMES. LES ETUDES CINETIQUES DE FORMATION ET D'HYDROLYSE ACIDE DES COMPLEXES PERMETTENT UNE APPROCHE DU MECANISME DE FORMATION ET D'HYDROLYSE DU COMPLEXE. LE MECANISME EST EXPRIME EN TERME D'UNE SUCCESSION D'ETAPES DE FORMATION ET DE COUPURE DES LIAISONS N-FE ET O-FE. LA SECONDE PARTIE A ETE CONSACREE A L'ETUDE THERMODYNAMIQUE ET CINETIQUE DE LA COMPLEXATION DE L'ION FE#3#+ AVEC DES LIGANDS DE STRUCTURE TRIPODE O-TRENSOX ET N-TRENSOX A SOUS-UNITES 8-HYDROXYQUINOLEINE. LA CARACTERISATION DES LIGANDS AINSI QUE DES A PERMIS DE DETERMINER LES CONSTANTES D'EQUILIBRE ET D'OBTENIR EGALEMENT DES INFORMATIONS STRUCTURALES A L'AIDE DES METHODES SPECTROPHOTOMETRIQUES UV-VIS, IR ET POTENTIOMETRIQUES. LA CINETIQUE DE FORMATION DU COMPLEXE FE(O-TRENSOX) EN MILIEU ACIDE AINSI QUE SA CINETIQUE D'HYDROLYSE ACIDE ONT ETE ETUDIEES AFIN DE METTRE EN EVIDENCE LES MECANISMES DE COMPLEXATION DU FER PAR LE LIGAND ET DE SA SORTIE DE LA CAGE DE COORDINATION FORMEE PAR LE LIGAND. LES RESULTATS DES ETUDES CINETIQUES D'ECHANGES DE L'ION FE#3#+ ENTRE LA TRANSFERRINE, L'EDTA ET O-TRENSOX PERMETTENT DE PROPOSER UN MECANISME POUR L'ECHANGE DU FER ENTRE LA TRANSFERRINE ET LE LIGAND O-TRENSOX. LA TROISIEME PARTIE CONCERNE L'ETUDE THERMODYNAMIQUE ET CINETIQUE DE LA COMPLEXATION DU FER PAR UN LIGAND BIPHENOL ET SON HOMOLOGUE TRIPODE. CETTE ETUDE DE PHYSICO-CHIMIE EN SOLUTION PERMET DE MIEUX COMPRENDRE LES INTERACTIONS CATIONS METALLIQUES-LIGANDS DANS LES PERSPECTIVES DE CONCEPTION DE MOLECULES ACTIVES DANS LE DOMAINE DE LA SANTE ET DE L'AGROCHIMIE

Download or read book INTERACTIONS ENTRE LE FER III ET LES IONS NITRATE PHOSPHATE ET CARBOXYLATE written by Jérôme Rose and published by . This book was released on 1996 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: LES MECANISMES DE FORMATION DES COLLOIDES ET PARTICULES FORMES LORS DE L'HYDROLYSE DU FER(III) EN PRESENCE DE NITRATE, PHOSPHATE, CARBOXYLATE, SILICATE ONT ETE DETERMINES PAR EXAFS, DPAX ET IRTF. L'ETUDE DE L'HYDROLYSE PARTIELLE DU FER(III) EN PRESENCE DE NITRATE (ION PEU COMPLEXANT), MONTRE QUE LA STRUCTURE LOCALE DES COLLOIDES FORMES POUR DES TAUX D'HYDROLYSE (R=OH/FE) FAIBLES NE CORRESPOND PAS A CELLE DES DES OXYHYDROXYDES DE FER CRISTALLISES. LA PRESENCE DE PHOSPHATE LORS DE L'HYDROLYSE DE FER(III), QUANT A ELLE, INHIBE PARTIELLEMENT LA POLYMERISATION DU FER. L'HYDROLYSE DU FER EST BLOQUEE AU STADE DE DIMERE. LE PHOSPHATE EST ASSOCIE A DEUX OU TROIS DIMERES, EN FONCTION DU TAUX D'HYDROLYSE ET DE LA QUANTITE DE PHOSPHATE INITIALE (P/FE). POUR UN RAPPORT P/FE=0,2, LORSQUE LE TAUX D'HYDROLYSE AUGMENTE, LA STRUCTURE INTERNE DES COLLOIDES SE DENSIFIE (DIMENSION FRACTALE VARIANT DE 2,3 A 2,8), MAIS LA TAILLE DES OBJETS RESTE DE L'ORDRE DE 100-150 A. POUR UN RAPPORT P/FE=0,5, LA STRUCTURE DES COLLOIDES EST PLUS OUVERTE (DIMENSION FRACTALE DE 2) ET UN GEL SE FORME POUR R=2. EN CE QUI CONCERNE L'ADSORPTION DES IONS PHOSPHATES SUR LES OXYHYDROXYDES DE FER, IL APPARAIT QU'A PH 5, DES COMPLEXES DE TYPE BIDENTATE BINUCLEAIRE SE FORMENT, ALORS QU'A PH 10 SEULS DES MONODENTATES EXISTENT. LA MATIERE ORGANIQUE (MO) PRESENTE DANS LES EAUX DE SURFACE BLOQUE PARTIELLEMENT L'HYDROLYSE DU FER. LA SPECIATION DU FER SEMBLE DEPENDRE NON SEULEMENT DU RAPPORT MASSIQUE MO/FER MAIS AUSSI DE LA NATURE CHIMIQUE DE LA MO. DANS DES EAUX OU LA QUANTITE DE MO EST TRES FAIBLE, MAIS OU LE SILICIUM EST UN ELEMENT MAJEUR, IL APPARAIT QUE LE FER FORME DES PHASES AMORPHES AVEC LES IONS SIO#4.

Download or read book Water Research written by and published by . This book was released on 1994 with total page 832 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wine Chemistry and Biochemistry written by M. Victoria Moreno-Arribas and published by Springer Science & Business Media. This book was released on 2008-11-06 with total page 729 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to describe chemical and biochemical aspects of winemaking that are currently being researched. The authors have selected the very best experts for each of the areas. The first part of the book summarizes the most important aspects of winemaking technology and microbiology. The second most extensive part deals with the different groups of compounds, how these are modified during the various steps of the production process, and how they affect the wine quality, sensorial aspects, and physiological activity, etc. The third section describes undesirable alterations of wines, including those affecting quality and food safety. Finally, the treatment of data will be considered, an aspect which has not yet been tackled in any other book on enology. In this chapter, the authors not only explain the tools available for analytical data processing, but also indicate the most appropriate treatment to apply, depending on the information required, illustrating with examples throughout the chapter from enological literature.

Download or read book Biomaterials written by David Byrom and published by Springer. This book was released on 1991-06-18 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomaterials are produced from biological material and are used for their physical characteristics. This book looks at the range of biomaterials and their applications which range from the use of polysaccharides as thickening agents to the use of proteins as fibres and adhesives.

Download or read book Chemical Thermodynamics of Neptunium and Plutonium written by Robert J. Lemire and published by Elsevier. This book was released on 2001-08-26 with total page 876 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unlike earlier books in this series, this review describes the selection of chemical thermodynamic data for species of two elements, neptunium and plutonium. Although this came about more by circumstance than design, it has allowed for a more consistent approach to chemical interpretation than might have occurred in two separate treatments. It has also drawn attention to cases where the available data do not show expected parallels, and where further work may be useful to confirm or refute apparent differences in the behaviour of neptunium and plutonium.

Download or read book Heterogeneous and Liquid Phase Processes written by Peter Warneck and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: The "European Experiment on the Transport and Transformation of Environmentally Relevant Trace Constituents over Europe" (EUROTRAC) was established in 1986 to tackle the scientific problem and combine the expertise, knowledge and resources in Europe, in order to apply them over a large region covering the greater part of the continent. EUROTRAC is a coordinated multidisciplinary scientific research project involving field measurements, laboratory studies, instrument development and development of comprehensive computer models for the simulation of the physical and chemical processes in the lower atmosphere.

Download or read book Elemental Speciation in Human Health Risk Assessment written by P. Apostoli and published by World Health Organization. This book was released on 2006 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Definitions of species and speciation - - Strructural aspects of speciation - - Analytical techniques and methodology - - Bioaccessibility and bioavailability - - Toxicokinetics and biological monitoring - - Molecular and cellular mechanisms of metal toxicity - - Health effects - - Conclusions and recommendations.

Download or read book The Chemistry and Biology of Nitroxyl HNO written by Fabio Doctorovich and published by Elsevier. This book was released on 2016-09-01 with total page 425 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Chemistry and Biology of Nitroxyl (HNO) provides first-of-its-kind coverage of the intriguing biologically active molecule called nitroxyl, or azanone per IUPAC nomenclature, which has been traditionally elusive due to its intrinsically high reactivity. This useful resource provides the scientific basis to understand the chemistry, biology, and technical aspects needed to deal with HNO. Building on two decades of nitric oxide and nitroxyl research, the editors and authors have created an indispensable guide for investigators across a wide variety of areas of chemistry (inorganic, organic, organometallic, biochemistry, physical, and analytical); biology (molecular, cellular, physiological, and enzymology); pharmacy; and medicine. This book begins by exploring the unique molecule's structure and reactivity, including important reactions with small molecules, thiols, porphyrins, and key proteins, before discussing chemical and biological sources of nitroxyl. Advanced chapters discuss methods for both trapping and detecting nitroxyl by spectroscopy, electrochemistry, and fluorescent inorganic cellular probing. Expanding on the compound's foundational chemistry, this book then explores its molecular physiology to offer insight into its biological implications, pharmacological effects, and practical issues. - Presents the first book on HNO (nitroxyl or azanone), an increasingly important molecule in biochemistry and pharmaceutical research - Provides a valuable coverage of HNO's chemical structure and significant reactions, including practical guidance on working with this highly reactive molecule - Contains high quality content from recognized experts in both industry and academia

Download or read book Transport and Chemical Transformation of Pollutants in the Troposphere written by Peter Borrell and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: A major environmental concern is the increasing burden on all scales of photo-oxidants, acidifying substances and potential nutrients in the troposphere. These lead to episodes of summer smog, and appreciable damage to eco-systems both on land and at sea. Underlying the environmental effects is the complex scientific problem of linking the man-made and biological emissions to the myriad chemical reactions that transform the pollutants as they are transported to and deposited in the surroundings and also pristine areas remote from the sources. The project, the scientific results of which are described in this book, was set up to study the problem in an inter-disciplinary way by co-ordinating the work of more than 150 research groups in some 20 countries.

Download or read book Cytochrome P450 2E1 Its Role in Disease and Drug Metabolism written by Aparajita Dey and published by Springer Science & Business Media. This book was released on 2013-02-12 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book deals with various clinical aspects of cytochrome P450 2E1 (CYP2E1) which is a potent source for oxidative stress. Oxidative stress is critical for pathogenesis of diseases and CYP2E1 is a major contributor for oxidative stress. Several clinical disorders are associated with changes in regulation of CYP2E1 and the consequent abnormalities which include alcoholic liver disease, alcoholic pancreatitis, carcinogenesis, non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, obesity, hepatitis C virus infection, reproductive organ toxicity, hepatocellular and cholestatic liver cirrhosis, inhibition of bone repair, cross-tolerance in smokers and people treated with nicotine, disorders of central nervous system, changes in metabolism of protoxicants in the circulatory system and susceptibility to human papillomavirus infection. Hence, CYP2E1 emerges as a new and potent player in aggravating injury and furthering disease complications.

Download or read book Advances in Solid State Fermentation written by S. Roussos and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 641 pages. Available in PDF, EPUB and Kindle. Book excerpt: G.HAINNAUX Departement Milieu et Activites Agricoles, Centre ORSTOM, 911 Avenue d' Agropolis, B.P. 5045, 34032 Montpellier Cedex , France. Solid state fermentation, popularly abbreviated as SSF, is currently investigated by many groups throughout the world. The study of this technique was largely neglected in the past in European and Western countries and there is now a high demand for SSF, meaning in food, environment, agricultural, phannaceutical and many other biotechnological applications. It gives me satisfaction to note that the importance of this technique was realised at my department way back in 1975 since then, our team has put concentrated efforts on developing this technique. xvii Foreword Advances in Solid State Fermentation Foreword M. PUYGRENIER Agropolis Valorisation, Avenue d' Agropolis, 34394 Montpellier Cedex 5, France. On the name of the Scientific Community, I would like to express the wish that this International Symposium on SSF should be successful. Solid State Fermentation is part of biotechnology research. It consists on seeding solid culture medium with bacteria or fungi (filamentous or higher) and on producing, in this medium (solid components and exudates) metabolites and high value products. In fact, this process is very old. In older industries such the food and agricultural, this technique has been extensively used. An example of this is the production of pork sausages and Roquefort cheese. Pharmaceutical industry could make extensive use of SSF in the production of secondary metabolites of many kinds and development in this direction is soon expected.

Download or read book Nuclear Techniques in Animal Production and Health written by International Atomic Energy Agency and published by . This book was released on 1976 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil-plant animal relations regarding minerals; Trace elements in animal nutrition; Trace elements in animal nutrition; Calcium; Phosphorus and magnesium metabolism; Protein (nitrogen) metabolism - ruminants; Protein (nitrogen) metabolism - non-ruminants; Nuclear techniques in the control of parasitic infections; Animal endocrinology with special emphasis on radioimmunoassays.

Download or read book Guidelines for Mastering the Properties of Molecular Sieves written by Denise Barthomeuf and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low dimensionality is a multifarious concept which applies to very diversified materials. Thus, examples of low-dimensional systems are structures with one or several layers, single lines or patterns of lines, and small clusters isolated or dispersed in solid systems. Such low dimensional features can be produced in a wide variety of materials systems with a broad spectrum of scientific and practical interests. These features, in turn, induce specific properties and, particularly, specific transport properties. In the case of zeolites, low dimensionality appears in the network of small-diameter pores of molecular size, extending in one, two or three di mensions, that these solids exhibit as a characteristic feature and which explains the term of "molecular sieves" currently used to name these ma terials. Indeed, a large number of industrial processes for separation of gases and liquids, and for catalysis are based upon the use of this low dimensional feature in zeolites. For instance, zeolites constitute the first class of catalysts employed allover the world. Because of the peculiarity and flexibility of their structure (and composition), zeolites can be adapted to suit many specific and diversified applications. For this reason, zeolites are presently the object of a large and fast-growing interest among chemists and chemical engineers.

Download or read book NOx Related Chemistry written by and published by Academic Press. This book was released on 2015-01-08 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: NOx Related Chemistry is a volume of a series that presents timely and informative summaries of the current progress in a variety of subject areas within inorganic chemistry, ranging from bio-inorganic to solid state studies. This acclaimed serial features reviews written by experts in the field and serves as an indispensable reference to advanced researchers. Each volume contains an index, and each chapter is fully referenced.