Life on Mars?
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Extraterrestrial Environment↗
Biomedical subjects
A W Muller
Publications and source records attributed to A W Muller.
Hypothesis: the thermosynthesis model for the origin of life and the emergence of regulation by Ca2+.
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Adenosine Triphosphate↗
Were the first organisms heat engines? A new model for biogenesis and the early evolution of biological energy conversion.
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Biological Evolution↗
Determination of the corrosion rates of six dental NiCrMo alloys in an artificial saliva by chemical analysis of the medium using ICP-AES.
So that the influence of salivary components upon the corrosion rate of six dental NiCrMo alloys could be established, their mass loss was determined in a medium consisting of a modified Fusayama's artificial saliva to which 300 mg KSCN/L had been added (pH 5.0). Nickel was the main element released; its loss vs. immersion time curves on a log-log plot resembled straight lines. The total nickel losses after one week ranged from 0.4 to 12.5 micrograms/cm2. From the nickel loss, corrosion currents were calculated. The corrosion currents at 24 hours of immersion were up to 67% larger than the currents in a previous study of these alloys, where the medium consisted of a 20 mM KCI-5 mM phosphate buffer solution (pH 7). The alloys with the least molybdenum content showed the largest corrosion current increase.
Chromium Alloys↗
Electrical potentials of restorations in subjects without oral complaints.
The electrical potentials of 183 amalgam and 11 precious metal restorations, and one set of brackets, were measured. None of the 28 subjects had galvanism, leukoplakia, oral lichen planus, or toxic or allergic reactions to restorations. The potentials of the amalgam restorations increased with age, from about -350 mV NHE at 30 days, to about +100 mV NHE after more than 1000 days. In most subjects potential differences of more than 50 mV were present between restorations; this phenomenon is therefore assumed to be common in healthy populations.
Corrosion↗
The determination of the electrical potential of a metallic restoration in the oral cavity.
An improved method for measuring the electrical potential of a metallic restoration is proposed and tested. Care was taken to avoid disturbing the restoration surface, hence it was not cleaned or dried. The probe tip was a gold-plated pin, insulated from the saliva by soft wax. The probe was pressed through the wax on the restoration just before measurement. An Ag/AgCl reference electrode was in contact with the saliva. The probe and the tip of the reference electrode were disposable.
Dental Alloys↗
Thermosynthesis by biomembranes: energy gain from cyclic temperature changes.
A theoretical mechanism is described allowing biomembranes to convert heat into electrical energy during temperature cycling (thermosynthesis). Necessary conditions for thermosynthesis are a temperature dependent electrical capacity and a conductivity as low as that of artificial lipid bilayers. Temperature cycling, and consequently thermosynthesis, can take place in leaves during cyclic transpiration and in organisms in natural waters that are carried along by convection currents. Electrogenic ATPases can convert the electrical energy gained by thermosynthesis into ATP if their activity and stoichiometry are properly regulated. The power of thermosynthesis is discussed and its possible value compared with the power of respiration. Environments where thermosynthesis may occur are listed. Thermosynthesis is a plausible energy source for the first living organisms.
Adenosine Triphosphatases↗