-Metacelsus-
u/-Metacelsus-
Slate Star Codex was a blog by Scott Alexander about human cognition, politics, and medicine. He now blogs at Astral Codex Ten: https://astralcodexten.substack.com/
Slate Star Codex was a blog by Scott Alexander about human cognition, politics, and medicine. He now blogs at Astral Codex Ten: https://astralcodexten.substack.com/
Yeah, I don't think polycarbonate polymers (or other large polymers) themselves are particularly dangerous chemically. Degradation products are the main concern. But since microplastics have a large surface area there is a lot of degradation going on.
Slate Star Codex was a blog by Scott Alexander about human cognition, politics, and medicine. He now blogs at Astral Codex Ten: https://astralcodexten.substack.com/
Slate Star Codex was a blog by Scott Alexander about human cognition, politics, and medicine. He now blogs at Astral Codex Ten: https://astralcodexten.substack.com/
If someone told me I should be worried about a stable polymer because of negative results found for a bisphenol, I would assume they had no chemistry background at all.
because BPA is a plasticiser,
BPA is not a plasticizer, you're thinking of phthalates. BPA is a monomer used in polycarbonate production. When polycarbonate plastics degrade, BPA can be released.
And I do have a chemistry background, FWIW
Slate Star Codex was a blog by Scott Alexander about human cognition, politics, and medicine. He now blogs at Astral Codex Ten: https://astralcodexten.substack.com/
Slate Star Codex was a blog by Scott Alexander about human cognition, politics, and medicine. He now blogs at Astral Codex Ten: https://astralcodexten.substack.com/
Speaking as a developmental biologist, I would disagree. Pre-gastrulation human embryos are not 1:1 equivalent with humans (the existence of identical twins disproves this). And they can't develop anyway without the mother's uterus. "Some assembly required" is making a huge stretch here.
Also, you could, in principle, epigenetically reprogram a blood cell to a human stem cell and create an artificial human embryo. It's not possible with current technology but there's no scientific reason it couldn't be done. (Although you'd want to use a blood cell that hasn't undergone VDJ recombination if you want the resulting human to have a working immune system).
Well, at least they used prisoners with vasectomies. But yeah, research ethics were not great at the time.
Spermatogonial stem cells can survive the elevated temperatures. So assuming this is a normal hot tub where the heat isn't enough to completely destroy your testes,* the sperm count will return to normal in a few months even if it drops temporarily. It takes about 64 days to go all the way from spermatogonial stem cells to sperm: https://pubmed.ncbi.nlm.nih.gov/13953583/
(Fun fact, this was measured in the 1960s by injecting prisoners' testicles with radioactive thymidine. The 1960s were wild!)
*And if it's not a normal hot tub, you'll have bigger problems.