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Biomedical subjects

E Thofern

Publications and source records attributed to E Thofern.

At least 37 records · Page 2Linked to original sources
PubMed1978

[Comparative investigations on the efficiency of chlorine and ozone against bacteria and spores (author's transl)].

This paper is concerned with the measurement of first order rate constants for the death of bacteria by chlorine and ozone. While the first order conditions for chlorine were achieved with the aid of a new instrument which works basing on the polarographic principle this was attained for ozone under steady state conditions. Besides differences of species some different properties for both oxidants were found as far as their bactericidal efficiency is concerned. They are discussed in this paper.

Bacillus cereus↗
PubMed1978

[Microorganisms in the open air during the period of a winter-half-year (author's transl)].

During the winter-half-year 1976/77 the concentrations of airborne microorganisms in the open air were measured in Bonn and at a place in the Sauerland. Simultaneously the data of wind direction, wind speed, atmospheric rel. humidity, temperature, intensity of solar radiation were registered. It can be shown, that the denominated parameters are influencing the content of microorganisms of the air in different proportions.

Air Microbiology↗
PubMed1978

[Influence of atmospheric aerosol materials on microorganisms (author's transl)].

The concentration of microorganisms showed variations over a wide range. As factors influencing their viability meteorological parameters as relative humidity and temperature were recognized. Furthermore there are other antimicrobial compounds in the air. For their demonstration the aerosol was collected on air filters and then extracted in aqueous solutions. Their examinations showed that there are geographic and seasonal dependences of the antimicrobial activity of the aerosol.

Air Microbiology↗
PubMed1978

[Microbial settlement of paint- and building-materials in the sphere of drinking-water. 1. Information: long time observation of a bitumen paint in a drinking-water-reservoir (author's transl)].

In a drinking water reservoir with a freshly applied bituminous coating a microbial settlement was found on the walls. Its development was observed over a period of 23 months. The slime on the walls consisted of bacteria and fungi and was secondarily colonized by protozoa and nematodes. The quantities of the microbial coating decreased during a 12 months time. In the beginning of the time of observation a high number of bacteria was found in the water. The carbon fixed by the microbes came from fossile sources to an amount of 90%.

Bacteria↗
PubMed1978

[Microbial settlement of paint- and building-materials in the sphere of drinking-water. 2. Information: experimental examination of bitumen paint under working conditions (author's transl)].

A bituminous coating material for drinking water reservoirs was applied on testing plates for a microbial examination. In function of the chlorine content of the water a microbial slime layer could be found on the testing plates. The amount of slime became less in course of the time or was not produced at all, when the plates were desiccated before the experiment for some months. A slime layer could never be observed on plates of asbestos cement and polyacryl as inert materials for comparison. Different microbial populations were observed.

Coal Tar↗
PubMed1977

[On the determination of chlorine with a polarographic probe. 1st communication: Examination of the physical properties of the new instrument (author's transl)].

A new chlorine measuring device for the field use in the water plant praxis was tested. The portable instrument supplied with a selectively permeable membrane works basing on the polarographic principle and shall allow an easy and accurate measurement of the "disinfectingpower" of a water chlorination. In the 1st note most important possibilities of meter-default as dependence on streamvelocity of water, pH and temperature are described. Furter the phenomenon of hysteresis is demonstrated.

Chlorine↗
PubMed1977

[On the determination of chlorine with a polarographic probe. 2nd communication: experimental arrangement and results under application (author's transl)].

The examination of the physical properties of the instrument showed several possibilities of meter-error mainly due to constructive disadvantages. After having found this a special experimental arrangement was worked out to exclude errors. Then good linear correlations of the meter-reading and the analytical DPD-Method for free Chlorine were found for pH-values ranging from 3.7 to 11. Further the results of a test under practical conditions in a swimming pool are shown and the possibility to discriminate different types of waters by their chlorine demand under constant-titration.

Chlorine↗
PubMed1977

[Hygienic problems in intensive care units (author's transl)].

Microbiological tests have established that intensive care units act as a reservoir from which hospital infections spread. The mode of their spread is reviewed. The increased incidence of nosocomial infections to intensive care wards is attributable partly to deficient antisepsis and asepsis and partly to inadequate planning of the building and organization of these wards. Plans for two intensive care wards are put forward which would reduce the risk of contact, smear and air-borne infections. In the planning of these units greater attention than has so far been the case should be paid to preventing the spread of pathogenic micro-organisms.

Air Microbiology↗
PubMed1976

Disinfection procedures of fiberscopes in endoscopy departments.

Disinfection of fibre endoscopes was examined in 5 endoscopy departments during endoscopy sessions. On the endoscopes, especially in the instrument channels, Pseudomonas aeruginosa and Proteus species could be regularly found, in some cases also Enterobacter cloacae and Candida albicans. With the results of disinfection experiments, proposals are made to reduce the infection risk due to insufficiently disinfected instruments in endoscopy departments.

Bacteriological Techniques↗
PubMed1976

[On the effect of particulate airborne substances on various micro-organisms (author's transl)].

Experimental studies on the reaction of micro-organisms on fine-dust filters (type C) and high-efficiency particulate air filters (type R and S) have shown no evidence of a growth of microorganisms. Therefore efforts were aimed at detecting antimicrobial factors which were supposed to exist in the precipitated acidic continental aerosol. With this in mind, air filters from different locations and with service times were extracted in water and the extract was tested for its antimicrobial effects. Die-off rates are used to demonstrate the influence of such extracts with varying concentrations of substances and pH values on bacteria.

Aerosols↗