ABSTRACT
Probe beam deflection (PBD) techniques, both as cyclic voltadeflectometry (CVD) and chronodeflectometry (CD), were applied for the first time to the study of the electrochemistry of nanostructured Pt materials which are commonly used as electrocatalysts in fuel cells. The electrochemical surface reactions, including faradaic processes, double layer charging and specific anion adsorption were easily detected. Quantitative analysis of the chronodeflectometric data made possible to elucidate the dynamics of double layer charging in such materials and to determine the potential of zero charge (pzc) of the metal present either as a monolithic mesoporous material or as metal nanoparticles supported on carbon. The electro-oxidation of CO, adsorbed on nanostructured Pt, was also studied by CVD and CD being able to detect the formation of CO2 and H3O+ related with the nucleation and growth process which controls the rate of CO stripping. The interplay of Pt oxide formation and COad electrooxidation, both in potential and time, was detected indicating possible application of the technique to other electrocatalysts.
Subject(s)
Carbon Monoxide/chemistry , Electrochemistry/methods , Nanostructures/chemistry , Platinum/chemistry , Adsorption , Carbon Dioxide/chemistry , Catalysis , Electrodes , Oxidation-Reduction , Perchlorates/chemistry , Sulfuric Acids/chemistry , Surface PropertiesSubject(s)
Crowns , Dental Implants, Single-Tooth , Esthetics, Dental , Malocclusion/therapy , Tooth Attrition/therapy , Dental Prosthesis, Implant-Supported , Gingivectomy , Humans , Incisor , Male , Malocclusion/complications , Maxilla , Middle Aged , Occlusal Adjustment , Orthodontics, Corrective , Tooth Attrition/complicationsABSTRACT
The production of chicken chimeras using donor and acceptor cells which can be of opposite sex has necessitated the utilization of methods developed to distinguish the sex of chickens. We demonstrate one of these methods, based on the polymerase chain reaction which amplifies the EcoRI repeat unit of the fowl W chromosome, and how this technique may be used to sex various cell types in chickens as well as small numbers of blastodermal cells. Our results demonstrate the ability to sex chickens using EcoRI primers, specific for the W chromosome, from as little as 2 ng of female genomic DNA isolated from blood and feathers--the latter being the result of DNA extraction from only one feather. Also evident in this study is the detection of the W chromosome by PCR from approximately 50 blastodermal cells originating from the developing blastodisc at stage X.
