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  • 1995-1999  (11)
  • Polymer and Materials Science  (7)
  • Cardiac surgery  (2)
  • Origin assignment  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Multielement stable isotope ratio analysis of glycerol to determine its origin in wine (1998)
    Springer
    Zeitschrift für Lebensmittel-Untersuchung und -Forschung 207 (1998), S. 237-243 
    Details
    ISSN: 1431-4630
    Keywords: Key words 2H-Nuclear magnetic resonance ; 13C ; 18O-Isotope ratio mass spectrometry ; Glycerol ; Origin assignment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The adulteration of wine with glycerol is considered to be a problem in European wine-producing countries. The latest control methods are mainly based on the detection of impurities from commercial products, but suffer from the raising efficiency of the purification processes. As there is little chance of being able to identify glycerol from different sources on the basis of a method which uses only one isotope, a multielement approach was tested. Glycerol from wine showed the lowest relative enrichment with D, mainly in position C-2, a relatively high 18O content, and very negative δ13C values, which significantly correlated with those of ethanol from the same wines. The isotopic data of glycerol samples from different sources were in agreement with those given by indices of origin (impurities). These data allowed us to identify the origin of these glycerol samples, i.e. whether they were produced industrially or synthesised by animals or plants. Glycerol of plant origin was most similar to glycerol found in wine. The combination of several isotopic data by discriminance analysis yielded clusters of data obtained from glycerol samples of similar origin. Taking into account the characteristics of possible mixtures, proof that wine has been adulterated depends on the origin and isotope levels of the added compound. This study showed that it is possible to prove that wine has been adulterated with glycerol from other sources when the latter is present at a concentration of 15% of the total glycerol content.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002170050325
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  • 2
    Electronic Resource
    Electronic Resource
    Stable oxygen isotope content of water of EU data-bank wines from Italy, France and Germany (1999)
    Springer
    Zeitschrift für Lebensmittel-Untersuchung und -Forschung 208 (1999), S. 400-407 
    Details
    ISSN: 1431-4630
    Keywords: Key words Wine ; Oxygen isotopes ; Adulteration control ; Origin assignment ; European Union data bank
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The application of oxygen isotope analysis to wine water (according to EU regulation no. 822/97) to determine a wine's origin, and check that it has not been adulterated is gaining increasing importance in both laboratories and industry. Using samples of Italian, French and German wines from the EU wine data bank (EU-DB), good agreement between the results from participating laboratories was demonstrated. Close correlations between the oxygen isotope contents of must and related wine water were found for samples from all countries. Based on the results of the δ18O values for EU-DB wines from 1991 to 1996 from Italy, France and Germany, we describe and discuss the main factors which are responsible for the variation of the oxygen isotope ratios of wine water. The examination of spiked samples demonstrated the usefulness of δ18O analysis for the detection of the watering down of wine. The possibility of origin assignment, preferably if the determination of the δ18O value by isotope ratio mass spectrometry (IRMS) is employed together with the determination of the site-specific hydrogen isotope content of wine ethanol by 2H-NMR and the measurement of δ13C values of ethanol by IRMS, is outlined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002170050437
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  • 3
    Electronic Resource
    Electronic Resource
    Effects of continuous (CPAP) and bi-level positive airway pressure (BiPAP) on extravascular lung water after extubation of the trachea in patients following coronary artery bypass grafting (1996)
    Springer
    Intensive care medicine 22 (1996), S. 1345-1350 
    Details
    ISSN: 1432-1238
    Keywords: Weaning CPAP ; BiPAP ; Extravascular lung water ; Cardiac surgery
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective To evaluate the effects of continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BiPAP) on extravascular lung water during weaning from mechanical ventilation in patients following coronary artery bypass grafting. Design Prospective, randomized clinical study. Setting Intensive care unit at a university hospital. Patients Seventy-five patients following coronary artery bypass grafting. Interventions After extubation of the trachea, patients were treated for 30 min with CPAP via face mask (n=25), with nasal BiPAP (n=25), or with oxygen administration via nasal cannula combined with routine chest physiotherapy (RCP) for 10 min (n=25). Measurements and results Extravascular lung water (EVLW), pulmonary blood volume index (PBVI) and cardiac index (CI) were obtained during mechanical ventilation (T1), T-piece breathing (T2), interventions (T3), spontaneous breathing 60 min (T4) and 90 min (T5) after extubation of the trachea using a combined dye-thermal dilution method. Changing from mechanical ventilation to T-piece breathing did not show any significant differences in EVLW between the three groups, but a significant increase in PBVI from 155±5 ml/m2 to 170±4 ml/m2 could be observed in all groups (p〈0.05). After extubation of the trachea and treatment with BiPAP, PBVI decreased significantly to 134±6 ml/m2 (p〈0.05). After treatment with CPAP or BiPAP, EVLW did not change significantly in these groups (5.5±0.3 ml/kg vs 5.0±0.4 ml/kg and 5.1±0.4 ml/kg vs 5.7±0.4 ml/kg). In the RCP-treated group, however, EVLW increased significantly from 5.8±0.3 ml/kg to 7.1±0.4 ml/kg (p〈0.05). Sixty and 90 min after extubation, EVLW stayed at a significantly higher level in the RCP-treated group (7.5±0.5 ml/kg and 7.4±0.5 ml/kg) than in the CPAP-(5.6±0.3 ml/kg and 5.9±0.4 ml/kg). No significant differences in CI could be observed within the three groups during the time period from mechanical ventilation to 90 min after extubation of the trachea. Conclusions Mask CPAP and nasal BiPAP after extubation of the trachea prevent the increase in extravascular lung water during weaning from mechanical ventilation. This effect is seen for at least 1 h after the discontinuation of CPAP or BiPAP treatment. Fuether studies have to evaluate the clinical relavance of this phenomenon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01709549
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  • 4
    Electronic Resource
    Electronic Resource
    Effects of continuous (CPAP) and bi-level positive airway pressure (BiPAP) on extravascular lung water after extubation of the trachea in patients following coronary artery bypass grafting (1996)
    Springer
    Intensive care medicine 22 (1996), S. 1345-1350 
    Details
    ISSN: 1432-1238
    Keywords: Key words Weaning ; CPAP ; BiPAP ; Extravascular lung water ; Cardiac surgery
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective: To evaluate the effects of continuous positive airway pressure (CPAP) and bi-level positive airway pressure (BiPAP) on extravascular lung water during weaning from mechanical ventilation in patients following coronary artery bypass grafting. Design; Prospective, randomized clinical study. Setting; Intensive care unit at a university hospital. Patients; Seventy-five patients following coronary artery bypass grafting. Interventions; After extubation of the trachea, patients were treated for 30 min with CPAP via face mask (n=25), with nasal BiPAP (n=25), or with oxygen administration via nasal cannula combined with routine chest physiotherapy (RCP) for 10 min (n=25). Measurements and results: Extravascular lung water (EVLW), pulmonary blood volume index (PBVI) and cardiac index (CI) were obtained during mechanical ventilation (T1), T-piece breathing (T2), interventions (T3), spontaneous breathing 60 min (T4) and 90 min (T5) after extubation of the trachea using a combined dye-thermal dilution method. Changing from mechanical ventilation to T-piece breathing did not show any significant differences in EVLW between the three groups, but a significant increase in PBVI from 155±5 ml/m2 to 170±4 ml/m2 could be observed in all groups (p〈0.05). After extubation of the trachea and treatment with BiPAP, PBVI decreased significantly to 134±6 ml/m2 (p〈0.05). After treatment with CPAP or BiPAP, EVLW did not change significantly in these groups (5.5±0.3 ml/kg vs 5.0±0.4 ml/kg and 5.1±0.4 ml/kg vs 5.7±0.4 ml/kg). In the RCP-treated group, however, EVLW increased significantly from 5.8±0.3 ml/kg to 7.1±0.4 ml/kg (p〈0.05). Sixty and 90 min after extubation, EVLW stayed at a significantly higher level in the RCP-treated group (7.5±0.5 ml/kg and 7.4±0.5 ml/kg) than in the CPAP-(5.6±0.3 ml/kg and 5.9±0.4 ml/kg) or BiPAP-treated groups (5.2±0.4 ml/kg and 5.2±0.4 ml/kg). No significant differences in CI could be observed within the three groups during the time period from mechanical ventilation to 90 min after extubation of the trachea. Conclusions: Mask CPAP and nasal BiPAP after extubation of the trachea prevent the increase in extravascular lung water during x weaning from mechanical ventilation. This effect is seen for at least 1 h after the discontinuation of CPAP or BiPAP treatment.Further studies have to evaluate the clinical relevance of this phenomenon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01709549
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  • 5
    Electronic Resource
    Electronic Resource
    Preparation and properties of composites of kevlar-nomex copolymer and boehmite (1997)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 248 (1997), S. 139-151 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Ein neuartiges organisch-anorganisches Hybridmaterial wurde durch den Einbau des Minerals Böhmit mittels eines Sol-Gel-Prozesses in ein Kevlar-Nomex-Copolymeres hergestellt. Durch Reaktion eines Gemisches aus m- und p-Phenylendiamin mit Terephthaloylchlorid und anschließender Umsetzung mit Aminophenyltrimethoxysilan wurden Poly(phenylenterephthalamid)-Ketten mit Aminophenyltri-methoxysilan-Endgruppen synthetisiert. In dieser Polymermatrix wurde die Hydrolyse der Alkoxygruppen einer Lösung von Aluminium-sec-butanolat in Butanol durchgeführt. Dadurch wurde ein chemisch an die Aramid-Ketten gebundenes anorganisches Netzwerk aufgebaut. Aus den hergestellten Hybridmaterialien mit unterschiedlichen Böhmit-Gehalten in der Aramidmatrix wurden Filme gegossen. Die Filme aus Hybridmaterial mit bis zu 15 Gew.-% Böhmit waren transparent gelb, während bei 20 und mehr Gew.-% Böhmit opake Filme erhalten wurden. Die mechanischen Eigenschaften dieser Filme wurden untersucht. Zugfestigkeit, Zugmodul, Härte und maximale Bruchdehnung nahmen mit steigendem Böhmitgehalt zunächst zu, vemngerten sich jedoch bei weiterer Erhöhung des Mineralanteils wieder. Der Zugmodul des Hybridmaterials bei 25°C lag zwischen 3,0 und 4,5 GPa. Die Materialien hielten einer maximalen Zugspannung von 252 MPa stand und zeigten Zersetzungstemperaturen von etwa 450°C. Die rnit DMTA ermittelten Werte für den Speichemodul lagen im Bereich 7,6-18,9 GPa. Das tan δ-Signal verbreiterte sich mit zunehmendem Böhmitanteil und ging bei hohen Böhmitgehalten in eine Schulter über. Die Signalpositionen des Verlustfaktors wurden infolge der zunehmenden sterischen Einschränkung der Segmentbewegungen rnit steigendem anorganischen Anteil zu höheren Temperaturen verschoben.
    Notes: A new organic-inorganic hybrid material was prepared by incorporating boehmite into a Kevlar-Nomex copolymer via a sol-gel process. Poly(phenylene-terephthalamide) chains having aminophenyltrimethoxysilane end groups were prepared by reacting a mixture of m-and p-phenylenediamine with terephthaloyl chloride, followed by end-capping with aminophenyltrimethoxysilane. The hydrolysis of the alkoxy groups of an aluminium sec-butoxide solution in butanol was carried out in the polymer matrix, thus creating an inorganic network structure combined chemically with the aramid chains. Hybrid materials containing different proportions of boehmite in aramid were thus produced and films were cast by solvent evaporation technique. These films with up to 15 wt.-% of boehmite were yellow and transparent, whereas the films with 20 wt.-% or more contents of boehmite were opaque. Mechanical properties of these films were analyzed. The values of tensile strength, initial modulus, toughness and maximum strain at rupture were initially found to increase and then decrease with further addition of boehmite. The tensile modulus of the hybrid material was found to be in the range of 3.0-4.5 GPa at 25°C. These ceramers were found to withstand maximum tensile stress of the order of 252 MPa, and the thermal decomposition temperature was around 450°C. The storage modulus as measured using DMTA was in the range of 7.6-18.9 GPa. The tan δ peak which in general became broader with increasing boehmite content showed a shoulder for composites containing large amounts of boehmite. The position of the peaks shifted towards high temperature with the increase in the inorganic contents showing hindrance in motion with increasing boehmite contents.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1997.052480109
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  • 6
    Electronic Resource
    Electronic Resource
    Neue Sol-Gel-Beschichtungen als Korrosions-und Verschleißschutz für NE-Metalle (1998)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 29 (1998), S. 23-29 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: New Sol-Gel Based Coatings as Corrosion- and Wear-Protection On Non-Ferrous MetalsA new composite coating material has been developed for the protection of non-ferrous alloys (e.g. aluminum, magnesium, zinc and brass). The coating materials were prepared by the solgel process from epoxyalkoxysilanes and aromatic diols to act as crosslinking agents. As solvent, alcohols and glycol ethers have been used.The viscosity of the system (7-55 mPas) was established in a way to be used in spray, dip or flow coating processes. The transparent coatings were cured at T = 100-220°C. In corrosion tests, 3000 hours salt-spray climate and 240 hours CASS-test = Copper chloride and Acetic acid added Salt Spray, no infiltration of the metal-coating interface and no „filiform-corrosion“ on A199.5, AlMg3 and AlMgSil was observed. Brass samples showed less than 4 mm extension of a scribe after 500 hours salt-spray-test. The coatings showed no visible traces of abrasion after 1000 cycles taber abrader test and an excellent adhesion (cross cut and tape-test: grade 0). The transparent basic systems were pigmented by 5 - 10 wt.% of colored organic pigments to obtain all kind of colored coatings.
    Notes: Es wurde ein neuer Beschichtungswerkstoff auf Basis von anorganisch-organischen Kompositen zum Schutz von Metalloberflächen, besonders von Aluminium entwickelt. Das Beschichtungsmaterial wurde über den Sol-Gel-Prozeß synthetisiert, ausgehend von Epoxy-funktionalisierten Alkoxysilanen und aromatischen Diolen als Quervernetzer. Als Lösungsmittel wurden Alkohole und Glykolether verwendet.Die Viskosität der Systeme wurde so eingestellt, daß sowohl Sprüh-, als auch Tauch- und Flut-Beschichtungen durchgeführt werden konnten. Sie lag zwischen 7 und 55 mPas. Nach dem thermischen Verdichtungsprozeß bei 100-220°C wurden transparente Beschichtungen mit ausgezeichneter Haftung auf Al-Mg-, Zn-und Messing-Oberflächen (Gitterschnitt- und Tape-Test: Klasse 0) erhalten. Die Korrosionsfestigkeit beschichteter Aluminiumlegierungen (Al 99.5, AlMg3, AlMgSi I) wurde mit dem Salzsprühverfahren (DIN 50021) und dem CASS-Test (NaCl, CuCl2·2H2O, Essigsäure, pH=3) geprüft und auch nach 3000 Stunden trat keine Unterwanderung der Grenzfläche Metall / Schicht auf. Ebenso wurde keine „Filiform“-Korrosion beobachtet. Messingproben zeigten nach 500 h Salzsprühnebel-Test weniger als 4 mm mittlere Unterwanderungsbreite. Darüber hinaus wurde die Abriebbeständigkeit der Proben überprüft. Die Schichten zeigten keine sichtbare Beschädigung nach Prüfung des Abriebes mit dem Reibradverfahren (1000 Zyklen, Räder: CS 10-F).Es konnten stabile Dispersionen von organischen Farbpigmenten im transparenten Basissystem hergestellt werden, wodurch eine große Vielfalt farbiger Beschichtungen erhalten wurde.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19980290108
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  • 7
    Electronic Resource
    Electronic Resource
    Modifikation von Titan durch Ionenimplantation-Ein Überblick (1997)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 28 (1997), S. 88-97 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Modification of Titanium by Ion Implantation-A ReviewThis paper reviews investigations concerning the effect of ion implantation on the properties of titanium alloys. The correlations between the process parameters and the phase formation in implanted layers, the wear and strength properties as well as the corrosion and oxidation behaviour are described. The application for joint prostheses is mentioned.
    Notes: Es wird ein Überblick über den Einfluß der Ionenimplantation auf die Eigenschaften von Titanlegierungen gegeben. Die Beziehungen zwischen den Prozeßparametern und der Phasenbildung in ionenimplantierten Schichten, den Verschleiß- und Festigkeitseigenschaften sowie dem Korrosions- und Oxidationsverhalten werden dargestellt. Die Anwendung für Gelenkprothesen wird kurz besprochen.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19970280210
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  • 8
    Electronic Resource
    Electronic Resource
    Gefüge und Korrosionsverhalten eines stickstofflegierten rostfreien Stahls (1998)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 29 (1998), S. 329-335 
    Details
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Microstructure and Corrosion Behaviour of a Nitrogen Alloyed Stainless SteelThe corrosion behaviour of a nitrogen alloyed stainless steel is investigated using potentiodynamic anodic polarization in physiological NaCl solution. The microstructure of forged samples is determined by microscopy and hardness measurements. The steel shows a globular austenitic structure. In the zone of large forging deformation the grains are elongated. Precipitates are observed in which chromium and molybdenium are enriched. The breakdown potentials range from 200 to 1170 mV vs. SCE, most of the values exceed 500 mV. The breakdown potentials decrease with increasing aspect ratio of the grains and increasing hardness. The precipitates are initial sites for pitting and crater shaped metal dissolution.
    Notes: Das Korrosionsverhalten eines stickstofflegierten rostfreien Stahles wird durch potentiodynamische anodische Polarisation in physiologischer NaCl-Lösung untersucht. Der Gefügezustand geschmiedeter Proben wird mikroskopisch und durch Härtemessungen ermittelt. Der Stahl weist ein globulares austenitisches Gefüge auf, in der Zone starker Schmiedeverformung sind die Körner gestreckt. Es liegen Ausscheidungen vor, in denen Chrom und Molybdän angereichert sind. Der Stahl zeigt Durchbruchspotentiale zwischen 200 und 1170 mV vs. SCE, die meisten Werte liegen über 500 mV. Die Durchbruchspotentiale fallen mit zunehmendem Streckungsgrad der Körner und zunehmender Härte ab. Die Ausscheidungen sind Initialpunkte für loch- und kraterförmigen Materialabtrag.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mawe.19980290704
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  • 9
    Electronic Resource
    Electronic Resource
    Photochromic Organic-Inorganic Nanocomposites as Holographic Storage Media (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Advanced Materials for Optics and Electronics 7 (1997), S. 123-133 
    Details
    ISSN: 1057-9257
    Keywords: nanocomposites ; sol-gel ; heteropolymetallates ; photochromics ; holographic data storage ; amplitude grating ; two-wave-mixing recording ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: This paper describes the properties of some new organic-inorganic photochromic layers. They are based on a hybrid organic-inorganic matrix in which tungsten heteropolyoxometallates (SiW12O4-40, PW12O3-40) are entrapped in a network obtained from the reaction of 3-glycidoxy-propyltrimethoxysilane. The high homogeneity of these materials on the nanoscale leads to transparent monoliths and layers of controlled thicknesses up to 40 μm. The optical properties of the blend are emphasised and the construction of amplitude gratings in the materials by two-wave-mixing experiments is described. The results of the optical experiments and the comparison with the theoretical background are used as a model for photochromic holographic storage processes. © 1997 John Wiley & Sons, Ltd.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Surface-modified gold electrodes for electrocatalytic oxidation of NADH based on the immobilization of phenoxazine and phenothiazine derivatives on self-assembled monolayers (1995)
    Weinheim : Wiley-Blackwell
    Electroanalysis 7 (1995), S. 46-54 
    Details
    ISSN: 1040-0397
    Keywords: Biosensors ; Self-assembly monolayers ; NADH ; Phenoxazines ; Phenothiazines ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Self-assembled monolayers of cystamine and cysteine chemisorbed on gold electrode surfaces have been used as a support for covalent immobilization of some phenoxazine and phenothiazine derivatives. The covalent attachment was achieved after previous functionalization of the free amino groups on the electrode surface with bifunctional reagents (terephthaloyl chloride and 1,6-hexamethylene diisocyanate) able to react with the imino form of the amino group in position 3 of the phenoxazine and phenothiazine derivatives.In every case, a shift of the redox potentials between 130 and 180 mV towards more positive potentials, as well as an increase in the peak-topeak separation between anodic and cathodic peaks was observed after covalent attachment. The surface coverages (10-11 〈 Γ 〈 10-10 mol/cm2) obtained from the cyclic voltammograms were those for a not densely packed monolayer and varied depending on the redox compound immobilized. The surface-modified electrodes obtained were afterwards used for the electrocatalytic oxidation of NADH.UV-vis spectroscopy was used to monitor the successive steps of surface modification using gold semitransparent electrodes. The total surface coverage of redox mediator on the electrode surface could also be calculated from the optical difference spectra between the oxidized and the reduced state obtained ‘in situ’ in a spectroelectrochemical cell.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/elan.1140070105
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