T
twilyth
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If it's really as bad as indicated, this is some worrisome news. Apparently, DNA breaths, in the sense that it spontaneously zips and unzips every few nanoseconds (see - http://www.plosone.org/article/info:doi/10.1371/journal.pone.0015806). When hit with terahertz radiation, it can prompt this unzipping to happen when it shouldn't. This can result in cells being reprogrammed.
article excerpt
Images From the PLOS ONE article
article excerpt
But what of the health effects of terahertz waves? At first glance, it's easy to dismiss any notion that they can be damaging. Terahertz photons are not energetic enough to break chemical bonds or ionise atoms or molecules, the chief reasons why higher energy photons such as x-rays and UV rays are so bad for us. But could there be another mechanism at work?
The evidence that terahertz radiation damages biological systems is mixed. "Some studies reported significant genetic damage while others, although similar, showed none," say Boian Alexandrov at the Center for Nonlinear Studies at Los Alamos National Laboratory in New Mexico and a few buddies. Now these guys think they know why.
Alexandrov and co have created a model to investigate how THz fields interact with double-stranded DNA and what they've found is remarkable. They say that although the forces generated are tiny, resonant effects allow THz waves to unzip double-stranded DNA, creating bubbles in the double strand that could significantly interfere with processes such as gene expression and DNA replication. That's a jaw dropping conclusion.
And it also explains why the evidence has been so hard to garner. Ordinary resonant effects are not powerful enough to do do this kind of damage but nonlinear resonances can. These nonlinear instabilities are much less likely to form which explains why the character of THz genotoxic
effects are probabilistic rather than deterministic, say the team.
This should set the cat among the pigeons. Of course, terahertz waves are a natural part of environment, just like visible and infrared light. But a new generation of cameras are set to appear that not only record terahertz waves but also bombard us with them. And if our exposure is set to increase, the question that urgently needs answering is what level of terahertz exposure is safe.
Images From the PLOS ONE article
a) THz radiation was generated by a frequency-doubling BBO crystal, in Argon at 600 torr pressure, with 1 KHz repetition rate [31]. The irradiated and control cells were in thermal contact and the temperature of both samples was monitored by themosensors. b) Mouse stem cells were monitored by light microscopy for morphological changes in response to THz exposure. A significant accumulation of lipid-like droplets in the cellular cytoplasm was visible in response to 6 hours of THz irradiation. Representative photographs are shown with 100x magnification for: Cells without THz exposure; cells after 2 hours of THz exposure; and cells after 6 hours THz exposure. Cells with an increased number of lipid-like droplets inclusions in the cytosol are indicated with black arrow; orange arrows – undifferentiated cells; white arrows – initial stage of adipogenesis.
a) Gene expression profiling of MSC cells in response to 9 hours of THz exposure. Of ~21,000 annotated genes represented in the Affymetrix mouse genome microarray, 1050 were underexpressed (red) and 1154 were overexpressed (green) with statistical significance p<0.05 as compared to the non-irradiated parallel control; b) RT-PCR measurement for selected genes. The relative level of gene expression in response to 9 hours exposure of MSC to THz radiation normalized to the TBP gene. The identity of the genes is shown below the bars. Cells without THz treatment served as control. The experimental results are consistent between three independent RT-PCR measurements in duplicates and in two different sets of irradiation. Brown bars – THz irradiated cells; blue bars – control cells. The table lists the S-Scores (representing the change in expression level in response to THz irradiation compared to the nonirradiated control) for these genes derived from the Affymetrix mouse genome microarray. c) The temperature was monitored using an IR detector, and separately using thermo-sensors glued to the outside of the petri dish lids. The temperature at the end of irradiation for the control plate with cells (c-79.40F) and the THz irradiated cells (THz-79.90F) is shown above the snap shots panels (snap shots are from the IR detectors in Fahrenheit). d) RT-PCR measurements for selected genes in response to 2, 4, and 9 hours irradiation. RNA levels are normalized to the TBP gene. The identity of the gene is shown at the top. The duration of irradiation is shown below the bars in hours (h). The number of specific transcripts is shown on the vertical axis in relative units [R.U.]. The RT-PCR results are consistent between two independent sets of measurements in duplicates.
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