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Medical/biological study (experimental study)

Experimental evidence for coherent excitations correlated with cell growth.

Published in: Nanobiology 1992; 1: 163-176
Journal partially peer-reviewed/unclear

Aim of study (acc. to author)

To investigate the influence of microwave irradiation on the cell growth of the yeast Saccharomyces cerevisiae.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 41.6965 GHz
Exposure duration: continuous for 10 h
Exposure 2: 41.6965 GHz
Exposure duration: continuous for 10 h
General information
A total of 37 growth experiments were conducted at 1 nW/cm², 27 with and 10 without MW radiation. Further 33 runs were performed at 5 pW/cm².
Exposure 1
Main characteristics
Frequency 41.6965 GHz
Type
Polarization
Exposure duration continuous for 10 h
Additional info Several frequencies between 41.688 and 41.707 GHz were applied.
Modulation
Modulation type cf. additional info
Additional info modulated at 8 kHz, square wave
Exposure setup
Exposure source
  • radiating slot of a gold-coated quartz needle
Chamber The thermostatted metallic irradiation chamber, coupled by a flexible waveguide with a standardised millimeter wave set-up [Grundler et al., 1983], was mounted on the stage of a scanning microscope.
Setup The radiation was guided through a tapered gold-coated quartz needle broadened by quartz carrier plates on both sides and radiated out of a slot (0.4 mm x 1.7 mm) on which the cells were spread in a monolayer. Yeast cells were fixed to the lower surface of a thin transparent agar layer (0.2 mm) filling the inner part of a smaller plastic ring. The agar layer and the cells rested on the quartz needle and the carrier plates. At the opposite surface of the quartz needle, a broader opening for microscopic viewing was covered with a fine metallic mesh suppressing RF leakage.
Additional info The MW field in the radiating slot was monomodal, and the EF was polarized in the y direction, surrounded by the MF in the x-z plane.
Parameters
Measurand Value Type Method Mass Remarks
power density 1 nW/cm² mean measured - -
SAR 0.04 µW/g mean - - -
Measurement and calculation details
The sin² intensity distribution of the λ/2 slot was determined by measuring input, transmitted and radiated powers.
Exposure 2
Main characteristics
Frequency 41.6965 GHz
Type
Polarization
Exposure duration continuous for 10 h
Additional info Several frequencies between 41.688 and 41.704 GHz were applied.
Modulation
Modulation type cf. additional info
Additional info modulated at 8 kHz, square wave
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 0.005 nW/cm² mean measured - -
SAR 0.2 nW/g mean - - -

Methods Endpoint/measurement parameters/methodology

Investigated material:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

Microwave exposure affects the cell growth rate of the yeast S. cerevisiae in a frequency and intensity dependent manner. Cell growth was either increased or decreased in a range of 10-20%.
Study character:

Study funded by

  • Deutsche Forschungsgemeinschaft (DFG; German Research Foundation)
  • Stiftung zur Förderung der Erfahrungsheilkunde im Stifterverband für die Deutsche Wissenschaft, Germany

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