[My Note: Unfortunately, I fear the lunatic fringe will once again interpret this interesting new work by Dr. Alexandrov, et. al., to mean that THz scanners are inanately harmful to people . Please note however, that the effects demonstrated occurred after very high levels of THz irradiation were prolonged over 2 continuous hours upon the subject mice. For some perspective on current scanners, please read Dr. Irl Dulings comments found on this blog, on Jan. 6th, 2011. http://terahertztechnology.blogspot.com/2011/01/dr-ira-duling-director-of-terahertz.html]
We report that terahertz (THz) irradiation of mouse mesenchymal stem cells (mMSCs) with a single-frequency (SF) 2.52 THz laser or pulsed broadband (centered at 10 THz) source results in irradiation specific heterogenic changes in gene expression. The THz effect depends on irradiation parameters such as the duration and type of THz source, and on the degree of stem cell differentiation. Our microarray survey and RT-PCR experiments demonstrate that prolonged broadband THz irradiation drives mMSCs toward differentiation, while 2-hour irradiation (regardless of THz sources) affects genes transcriptionally active in pluripotent stem cells. The strictly controlled experimental environment indicates minimal temperature changes and the absence of any discernable response to heat shock and cellular stress genes imply a non-thermal response. Computer simulations of the core promoters of two pluripotency markers reveal association between gene upregulation and propensity for DNA breathing. We propose that THz radiation has potential for non-contact control of cellular gene expression.
[here are Dr. Duling's earlier comments from 2011:
This morning, I received the following email from Dr. Irl Duling, who is the Director of Terahertz Business Development for Picometrix, LLC (an API company), discussing how the THz radiation emitted by the T-Ray 4000, developed at Picometrix, compares to the THz radiation used in the above study:
" To compare the exposures that are used (in the article you have referenced,) with what is emitted by the T-Ray 4000 equipment:
Average power is the amount of energy per second emitted in a beam (integrated over time).
The average power of the source used in this paper is 1 milliwatt, while our equipment puts out 1 microwatt (1000 times less).
More importantly, the energy emitted by the source in this paper puts that energy into 1000 pulses per second, while our source spreads the energy over 50,000,000 pulses per second. The consequence is that the peak power of each pulse in the study is 50,000,000 times higher than the pulses emitted from our equipment. The difference is like tapping on your hand rapidly with a pencil or repeatedly dropping a locomotive on it.
Even at this level of impact, it took 9 hours to see an effect.
Best regards,
Irl Duling
--
Irl Duling, PhD
Director of Terahertz Business DevelopmentPicometrix, LLC (an API company)"]
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