ELECTRODES A PATE DE CARBONE MODIFIEES PAR UNE OU DEUX ENZYMES (GOD PDF Download

Author: ANITA.. RONDEAU
Publisher:
ISBN:
Category :
Languages : fr
Pages : 178

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CE MEMOIRE PRESENTE UNE ETUDE APPROFONDIE DES CAPACITES DES ELECTRODES A PATE DE CARBONE MODIFIEES, A OPERER DANS DES CONDITIONS DYNAMIQUES, PLUS PRECISEMENT EN ANALYSE PAR INJECTION EN FLUX CONTINU (FIA). L'OBJECTIF PRINCIPAL DE CE TRAVAIL RESIDE DANS LA MISE AU POINT DE BIOCAPTEURS AMPEROMETRIQUES PERFORMANTS POUR LE DOSAGE DU GLUCOSE EN FIA. L'ELECTRODE A PATE DE CARBONE, MODIFIEE PAR L'ENZYME GLUCOSE OXYDASE (GOD) ET LE MEDIATEUR FERROCENE (FCH), OPTIMISEE POUR LE DOSAGE DU GLUCOSE EN CONDITIONS STATIONNAIRES, N'EST PAS PERFORMANTE EN FIA, A CAUSE DE LA FUITE DE SES DIFFERENTS COMPOSANTS, ET D'UN PROBLEME DE GONFLEMENT DE SURFACE. SUITE A UNE MEILLEURE RETICULATION DE L'ENZYME, A UN CHANGEMENT DE LA NATURE DU LIANT, A L'INCORPORATION D'UN SURFACTANT, POUR AUGMENTER LA SOLUBILISATION DU FCH, ET SURTOUT SUITE A L'APPLICATION D'UN FAIBLE POTENTIEL (0 V / AG/AGCL), QUI MINIMISE LA FUITE DU MEDIATEUR, IL A ETE POSSIBLE D'OPTIMISER UN BIOCAPTEUR, PRESENTANT DES PERFORMANCES ANALYTIQUES ACCEPTABLES. AU COURS DE CE TRAVAIL, UN PHENOMENE DE PRECONCENTRATION OU EFFET EPONGE DE L'HYDROXYMETHYL FERROCENE (FCCH 2OH), A ETE OBSERVE PAR VOLTAMMETRIE CYCLIQUE, SUITE A FAIBLE POTENTIEL, SUR UNE ELECTRODE A PATE DE CARBONE MODIFIEE PAR DES PROTEINES (GOD-BSA). L'ACCUMULATION SE FAIT A PRIORI PAR LE LIANT, MAIS LE ROLE IMPORTANT DES PROTEINES SERA EGALEMENT DISCUTE. ENFIN, UNE AUTRE ALTERNATIVE A ETE PROPOSEE POUR DEVELOPPER UN BIOCAPTEUR, BASE SUR UNE ELECTRODE A PATE DE CARBONE, APPLICABLE POUR LE DOSAGE DU GLUCOSE EN FIA. L'INTRODUCTION DE L'ENZYME PEROXYDASE (HRP) DANS LE SYSTEME (GOD-FCH), PERMET UNE DETECTION EN REDUCTION DU MEDIATEUR, QUI LIMITE AINSI SA FUITE EN SOLUTION AQUEUSE.

Author: Anita Rondeau
Publisher:
ISBN:
Category :
Languages : fr
Pages : 82

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Author:
Publisher:
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Category : Chemistry
Languages : en
Pages : 620

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Author: SOPHIE.. GUEGUEN
Publisher:
ISBN:
Category :
Languages : fr
Pages : 156

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CE MEMOIRE PRESENTE UNE ETUDE RELATIVE AU DEVELOPPEMENT ET A L'OPTIMISATION DE BIOCAPTEURS AMPEROMETRIQUES A DES FINS ANALYTIQUES EN CONDITIONS STATIONNAIRES. L'OBJECTIF PRINCIPAL DE CE TRAVAIL RESIDE DANS LA MISE AU POINT D'ELECTRODES MONO OU MULTIENZYMATIQUES POUR LE DOSAGE DE CERTAINS GLUCIDES DANS DES MILIEUX ALIMENTAIRES, CECI EN EVALUANT LES PARAMETRES DE PRECISION TELLES QUE LA REPETABILITE ET LA JUSTESSE DES MESURES. AU COURS DE CE TRAVAIL ET DANS UN PREMIER TEMPS, LES CARACTERISTIQUES EN TERME DE STABILITE DE STOCKAGE DES ELECTRODES ONT ETE ANALYSEES ET UN MODELE MATHEMATIQUE A ETE ELABORE POUR RENDRE COMPTE DE LA PERTE DE L'ACTIVITE DES BIOCAPTEURS LORS DU VIEILLISSEMENT. LA CHUTE DE L'ACTIVITE DE LA SURFACE DE L'ELECTRODE N'A PAS ETE CORRELEE A UNE DENATURATION ENZYMATIQUE MAIS VRAISEMBLABLEMENT A UNE DIMINUTION DE LA CONCENTRATION DE MEDIATEUR DANS LA PATE DE CARBONE SUITE A UN PHENOMENE D'EVAPORATION. L'ELECTRODE A PATE DE CARBONE MODIFIEE PAR LA GLUCOSE OXYDASE ET LE FERROCENE, DESTINEE AU DOSAGE DU GLUCOSE, A CONSTITUE LE POINT DE DEPART POUR LA FABRICATION D'ELECTRODES MULTIENZYMATIQUES DESTINEES AU DOSAGE DU SACCHAROSE ET DU LACTOSE EN INCORPORANT LES ENZYMES MUTAROTASE, INVERTASE OU -GALACTOSIDASE. L'OPTIMISATION D'ELECTRODES MULTI-ENZYMATIQUES POUR DES MESURES DE GLUCIDES ALIMENTAIRES A MONTRE D'UNE PART L'IMPOSSIBILITE D'ATTEINDRE UN RENDEMENT D'HYDROLYSE DE 100% POUR LA MESURE DU SACCHAROSE ET D'AUTRE PART L'ECHEC DE PROVOQUER L'HYDROLYSE DU LACTOSE DU FAIT DE L'ABSENCE DE L'ACTIVITE DE LA -GALACTOSIDASE LORSQU'ELLE EST INTRODUITE DANS LA PATE DE CARBONE. NEANMOINS, CE TRAVAIL A PERMIS D'ETABLIR DES STRATEGIES ANALYTIQUES, EN COMBINANT LES ELECTRODES MONO OU MULTI-ENZYMATIQUES, ET CERTAINES ENZYMES EN SOLUTION, PERMETTANT DES DOSAGES PRECIS DANS LES MATRICES ALIMENTAIRES. LA METHODE AMPEROMETRIQUE PROPOSEE EST RAPIDE ET EST COMPARABLE EN TERME DE PERFORMANCES A LA METHODE SPECTROPHOTOMETRIQUE, LARGEMENT REPANDUE EN ANALYSE DE ROUTINE.

Author: Zdenek Sesták
Publisher: Springer Science & Business Media
ISBN: 9400991665
Category : Science
Languages : en
Pages : 309

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The bib I iography includes papers in alI fields of photosynthesis research - from stu dies of model biochemical and biophysical systems of the photosynthesis mechanism to primary production studied by the so-cal led growth analysis. In addition to papers devoted entirely to photosynthesis, papers on other topics are included if they con tain data on photosynthetic activity, photorespiration, chloroplast structure, chlo rophyl I and carotenoid synthesis and destruction; etc., or if they contain valuable methodo I og i ca I information (measurement of se I ected env i ronmenta I ·factors, I eat area, etc.). In many branches it has been very difficult to define the I imits of interest for photosynthesis researchers. This problem has arisen e. g. in topics dealing with the transport of gases, where- in addition to the papers on C0 transfer- some pa 2 pers on water vapour transfer are included, these being of general application. On the other hand, many papers dealing with the anatomy and physiology of stomata have been omitted, if the aspect of carbon dioxide or water vapour exchange has not been discussed. This volume contains references to papers pub I ished in the year 1976, and, similarly to Vol. 6, also addenda including references pub I ished in the preceding period (i. e. 1966- 1975). The numbers of these additional references are label led with an asterisk in the I ist of references.

Author: Zdenek Sesták
Publisher: Springer Science & Business Media
ISBN: 9401023298
Category : Science
Languages : en
Pages : 312

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It is generally accepted that photosynthesis, whereby solar is transformed into geobiochemical energy, is one of the most important processes in the bio sphere. When we realize that the human population, most of which is starving, wi I I double in 20-30 years, and that photosynthesis is in practice the only source (direct or indirect) of food not only for men, but for al I I iving beings, its im portance becomes even plainer. This fact was recognized from the outset of the International Biological Programme, when photosynthesis was selected as one of the principal problems to be concentrated on. The significance of the IBP in initiating a broader-based ap proach and worldwide collaboration need not be emphasized here; it is merely ne cessary to consider the rapid increase in the number of papers on photosynthesis since its inception. It is of fundamental importance for scientists working on photosynthesis to get information on what has been done in recent years in this discipl ine. Thus as complete as possible a bibl iography is badly needed. The complexity of this pro blem requires also that the progress of ecology, chemistry and physics, as far as they concern photosynthesis, be fol lowed. Such a bib I iography, covering at least the last ten years, wi I I be indispensable for final synthesis of the results of the IBP photosynthetic programme.

Author: Richard T. Addo
Publisher: Springer
ISBN: 3319476912
Category : Medical
Languages : en
Pages : 190

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The eye is a computerized system that has been designed for self-defense, and these defense mechanisms create challenges in administration of medications to the eye. Therefore, ocular drug delivery has been a major challenge to drug delivery researchers. There are on-going studies, in search of treatment especially for the diseases affecting the posterior segment of the eye. This book gives and overview of the background of ocular drug delivery and is unique for pharmacists, medical practitioners, students and drug delivery researchers.

Author: Léon Chertok
Publisher: Pergamon
ISBN:
Category : Psychology
Languages : en
Pages : 200

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Author: Mária Németh Lenke
Publisher:
ISBN:
Category : American drama
Languages : en
Pages : 164

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Author: Jim Keith
Publisher: Illuminet Press
ISBN: 9781881532217
Category : Political Science
Languages : en
Pages : 128

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The era of chemical and biological megadeath is upon us, and the potential of deadly biowarfare attacks from governments, militant independent groups, and even individuals is far greater than it has been at any time in the past. At this time, more than twenty-five countries are developing, or have stockpiles of chemical and biological weapons, in many cases in sufficient quantities to wipe out the entire population of the world. So far the danger of chemical and biological aggression has been little acknowledged, and, at least in America, little prepared for by federal and local government. Most terrorist threats and attacks are not widely reported in the mainstream media. Although information about the proliferation of man-made diseases is carefully suppressed by governments and the media they will be covered in the pages of this book. Not only is America unprepared and ignorant of what is happening, but the people in government and scientific professions who do know, who should be warning the American public about the dangers of chemical and biological terrorism, are instead doing their utmost to hide this information from us; information that is vital for our survival.The information that is contained in the pages of this book will not be measured or calculated to reassure people that everything is fine, when reassurance is the exact opposite of what is needed at this time. It may even give you nightmares when you realise the real circumstance that we are in. The information in the pages that follow will be the truth about the biowarfare threat to America.