ABSTRACT
Successful wound management is reported in a case of extended and life threatening necrotizing fasciitis of the leg of a poly-morbid older woman by use of standards of septic surgery (sufficient excision of necrotic tissue, use of bacteria adapted antibiotics, programmed wound revisions) and use of an industrial supplied device of vacuum assisted closure (V.A.C.).
Subject(s)
Fasciitis, Necrotizing/therapy , Occlusive Dressings , Aged , Anti-Infective Agents/therapeutic use , Chronic Disease , Combined Modality Therapy , Critical Care , Debridement , Female , Humans , Leg/surgery , Microbial Sensitivity Tests , Necrosis/surgery , Postoperative Care , Vacuum , Varicose Ulcer/complications , Varicose Ulcer/therapyABSTRACT
The surface modification of electrodes was achieved by the Langmuir-Blodgett technique. The monolayers of laponite clay and polythiophene were formed at the air-water interface and these films were then transferred onto carbon microelectrodes. The behaviour of both untreated and coated electrodes was tested by originally developed double-step voltcoulometry (DSVCM). The dependence of charge response on the concentration of Cu(2+) species was investigated. Straight calibration curves were obtained and enhanced sensitivity of coated electrodes was documented. It is shown that the accumulation of Cu ions into laponite clay was maintained even after transferring the electrode into a pure water. The characteristic features of the "memory effect" are discussed.
Subject(s)
Aluminum Silicates/chemistry , Metals/analysis , Microelectrodes , Calibration , Carbon , Cations , ClayABSTRACT
This paper presents a method for the analysis of drugs in dosage form. It is based on galvanostatic generation of oxidation agent from a suitable precursor on one segment of interdigitated microelectrode array (IDA) and its consecutive amperometric detection on second segment. High collection efficiency of this process in comparison to rotational ring disc electrode (RRDE) is a unique feature of IDA system. The transfer of oxidation agent can be influenced by addition of species, which reacts with oxidant. This influence can be used for its determination. Evaluation of generator-collector current dependence (diffusion layer titration curve) reveals the value of generator current I(genE) of the end-point of titration. I(genE) is proportional to the bulk phase concentration of determined species. The method was applied to the analysis of pharmaceuticals Antabus (Disulfiram Alpharma NOR, tetraethylthiuram disulfide (TETD)), a popular drug for alcoholism treatment, and Celaskon (vitamin C, Léciva CZE, ascorbic acid (AA)). From model samples analysis rather low detection limits, 9x10(-7) mol dm(-3), respectively, 4x10(-6) mol dm(-3), were estimated which enables trace content analysis of the drugs. A small size of IDA sensor also makes it suitable for microanalytical improvement.
ABSTRACT
An interdigitated microelectrode array (IDA) sensor has been applied to the determination of iodide in mineral water. It is based on reversible charge transfer in the redox system I2/2I- at a platinum microelectrode. The analytical signal from the IDA system was obtained by use of a bipotentiostat in dual mode. One segment of the IDA (generator) was polarized to the limiting current for oxidation of iodide to iodine in 0.1 mol L(-1) HClO4. The second segment (collector) was fixed at a potential value corresponding to the limiting current of iodine reduction. The geometrical arrangement of the IDA enables this transfer with high efficiency. Because the diffusion layer of both segments overlaps the iodide produced on the collector, the iodide diffuses back to the generator where it is reoxidized. Therefore, redox cycling will enhance the voltammetric signal of the IDA. The signal obtained with a vertically separated IDA was 20 times higher than that in the single mode. Because multiplication of the signal reduces the detection and determination limits, direct voltammetric determination of iodide in mineral water is possible.
