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G Luft

Publications and source records attributed to G Luft.

8 recordsLinked to original sources

Oxidative degradation of p-toluenesulfonic acid using hydrogen peroxide.

The oxidative degradation of p-toluenesulfonic acid using thermally activated hydrogen peroxide was investigated. The concentrations of all aromatic and aliphatic intermediates were determined by means of HPLC. From the identification of all intermediates, a detailed reaction mechanism for the oxidative degradation of p-toluenesulfonic acid is proposed. Experiments show that the oxidation with hydrogen peroxide is an effective process for the destruction of organic pollutants. Only substoichiometric amounts of hydrogen peroxide are required to convert this refractory model compound to easily biodegradable substances.

Benzenesulfonates↗

The electrocatalytic glucose sensor.

An electrocatalytic glucose sensor is a very useful component of an artificial beta cell in controlling the insulin dosage in the diabetes therapy. The advantage is its potential long-term stability and the disadvantage is its lack of selectivity. The principle and experimental results with different electrolytes will be described. In saline solution the mean deviation in glucose response is up to 15% if the amino acid and urea concentrations raise from minimum to their physiological maximum values.

Animals↗

In vitro activity of flomoxef compared to moxalactam, cefoxitin, cefotaxime, and clindamycin against anaerobes.

To assess the in vitro activity of flomoxef (6315-S), moxalactam, cefoxitin, cefotaxime, and clindamycin against anaerobes 197 clinical isolates (27 Bacteroides fragilis, 42 B. thetaiotaomicron, 10 B. vulgatus, 7 B. ovatus, 6 B. uniformis, 6 B. distasonis, 7 Bacteroides melaninogenicus group, 11 Bacteroides oralis group, 21 Clostridium difficile, 7 C. perfringens, 3 C. sporogenes, 3 Clostridium spp., 33 Propionibacterium acnes, 14 Peptococcaceae) were studied by means of agar dilution tests. The MIC90 of B. fragilis was less than 2 micrograms/ml for flomoxef, less than 4 micrograms/ml for moxalactam, less than 16 micrograms/ml for cefoxitin, less than 128 micrograms/ml for cefotaxime and less than 2 micrograms/ml for clindamycin. The respective MIC90's of B. thetaiotaomicron were less than 64, less than 128, less than 32, less than 256 and 8 micrograms/ml. Strains of the other Bacteroides species and groups were more susceptible to flomoxef and the other antibiotics than B. thetaiotaomicron. Against Clostridium difficile flomoxef (MIC90 less than 4 micrograms/ml) proved to be superior to the other agents tested. Most of the Clostridium strains other than C. difficile were also susceptible to flomoxef; anaerobic grampositive cocci and Propionibacterium acnes were very sensitive (MIC90's less than 1 and less than or equal to 0.125 micrograms/ml, respectively). Its anti-anaerobic activity, together with its efficacy against aerobes, should make flomoxef a useful adjunct to the arsenal of modern antibiotic therapy.

Anti-Bacterial Agents↗

Development of an electrocatalytic glucose sensor.

For the determination of glucose in body fluids, the electrocatalytic sensor, besides the enzyme sensor, is quite suitable, particularly for long-term intracorporeal operation. The measuring response is disturbed by the fluctuating concentrations of the interfering substances that are simultaneously present in body fluids. However, the disturbance can essentially be controlled, as is shown in the case of amino acids. Their marked influence on glucose oxidation is suppressed at a membrane-covered sensor electrode by the use of a potential step method.

Artificial Organs↗

Electrochemical behavior of amino acids and their influence on the anodic oxidation of glucose in neutral media.

Body fluids contain a large number of amino acids along with glucose. Therefore, the electrochemical behavior of amino acids should be considered in studying the anodic oxidation reaction of glucose for biological applications. Potential-sweep and steady-state measurements with different platinum electrodes under neutral conditions have shown that the oxidation of amino acids is basically possible. However, their presence, especially as a mixture, has a remarkable influence on the glucose oxidation and the anodic reaction is strongly inhibited. With respect to the degree of inhibition, they can be classified into two groups. The inhibiting effect is particularly drastic in the case of basic and unsaturated amino acids as well as the ones containing sulphur because of their strong absorption at the electrode surface. The glucose currents are inhibited by about 90% under steady-state. In addition to the direct electrochemical inhibition, the following bacterial decomposition of amino acids is probably also responsible for the drastic effect. However, about 10% of the glucose currents still remain measurable indicating that glucose is detectable at physiological concentrations even under extremly unfavorable conditions. This result is of basic importance in operating a biofuel cell or in measuring glucose concentrations.

Amino Acids↗

Development and present status of an electrocatalytic glucose sensor.

For the determination of glucose in body fluids the electrocatalytic sensor seems to be quite favorable, particularly for long-term intracorporeal operation. The measuring response is disturbed by the fluctuating concentrations of interfering substances that are present in body fluids. However, the disturbance can be for the most part controlled, as shown in the case of amino acids. Their marked influence on glucose oxidation is suppressed at a membrane-covered sensor electrode by using a potential step method.

Amino Acids↗