Ergothioneine is an emerging component of the redox homeostasis system in human cells and in microbial pathogens, such as Mycobacterium tuberculosis or Burkholderia pseudomallei. Synthesis of stable isotope labelled ergothioneine derivatives may provide important tools for deciphering the distribution, function and metabolism of this compound in vivo. We describe a general protocol for the production of ergothioneine isotopologues with programmable 2H, 15N 13C, 34S and 33S isotope labelling patterns. This enzyme‐based approach makes efficient use of commercial isotope reagents and is also directly applicable for the synthesis of radio‐isotopologues.
https://ift.tt/34rQ1Ll
See title!
For example: During evaporation from a body of water, the water vapor will be "depleted" in the heavier isotopologues - HDO and H2(18)O - and "enriched" in the light isotopologue - H2O. However, when looking at the isotopic composition of the vapor (assuming that all of the liquid water didn't evaporate), the HDO will actually be much more depleted than the H2(18)O!
I figure this has something to do with asymmetry of HDO compared to H2(18)O, but I cannot come up with a with a convincing explanation.
[edit]
Let me elaborate a bit, I was trying not to use esoteric terms to describe my problem and I think this lead to some confusion.
Take a sample of naturally occurring water, fill a bottle about half way, close the bottle, and hold temperature constant at 25C. Most of the water will be H2O. The next two most common isotopologues of water are, as above, HDO and H2(18)O. When allowed to reach equilibrium (i.e., humidity = 100%), the vapor will have been fractionated both for deuterium and for 18-Oxygen. Based on mass, I would expect that the HDO (mass = 19) would have been preferentially evaporated and moved into the vapor phase when compared to H2(18)O (mass = 20). However, just the opposite is true. At equilibrium, there will be about eight times less HDO in vapor phase than the heavier H2(18)O. What this means is that if started with SMOW (standard mean ocean water, delta D = 0.00 per mil and delta 18-O = 0.00 per mil), our vapor would have delta D = -79 per mil and delta 18-O = -9 per mil (these aren't the exact fractionation factors, but close enough). Our heavy isotopologue is actually more common in vapor phase than our relatively lighter isotopologue!
This is a commonly observed phenomena and is described in natural systems by the global meteoric water line.
[/edit]
I don't want to step on anybody's toes here, but the amount of non-dad jokes here in this subreddit really annoys me. First of all, dad jokes CAN be NSFW, it clearly says so in the sub rules. Secondly, it doesn't automatically make it a dad joke if it's from a conversation between you and your child. Most importantly, the jokes that your CHILDREN tell YOU are not dad jokes. The point of a dad joke is that it's so cheesy only a dad who's trying to be funny would make such a joke. That's it. They are stupid plays on words, lame puns and so on. There has to be a clever pun or wordplay for it to be considered a dad joke.
Again, to all the fellow dads, I apologise if I'm sounding too harsh. But I just needed to get it off my chest.
Do your worst!
I'm surprised it hasn't decade.
For context I'm a Refuse Driver (Garbage man) & today I was on food waste. After I'd tipped I was checking the wagon for any defects when I spotted a lone pea balanced on the lifts.
I said "hey look, an escaPEA"
No one near me but it didn't half make me laugh for a good hour or so!
Edit: I can't believe how much this has blown up. Thank you everyone I've had a blast reading through the replies 😂
It really does, I swear!
They’re on standbi
Pilot on me!!
Nothing, he was gladiator.
Dad jokes are supposed to be jokes you can tell a kid and they will understand it and find it funny.
This sub is mostly just NSFW puns now.
If it needs a NSFW tag it's not a dad joke. There should just be a NSFW puns subreddit for that.
Edit* I'm not replying any longer and turning off notifications but to all those that say "no one cares", there sure are a lot of you arguing about it. Maybe I'm wrong but you people don't need to be rude about it. If you really don't care, don't comment.
When I got home, they were still there.
What did 0 say to 8 ?
" Nice Belt "
So What did 3 say to 8 ?
" Hey, you two stop making out "
Because she wanted to see the task manager.
I won't be doing that today!
[Removed]
Where ever you left it 🤷♀️🤭
This morning, my 4 year old daughter.
Daughter: I'm hungry
Me: nerves building, smile widening
Me: Hi hungry, I'm dad.
She had no idea what was going on but I finally did it.
Thank you all for listening.
There hasn't been a post all year!
You take away their little brooms
It was about a weak back.
It’s pronounced “Noel.”
After all his first name is No-vac
What, then, is Chinese rap?
Edit:
Notable mentions from the comments:
-
Spanish/Swedish/Swiss/Serbian hits
-
French/Finnish art
-
Country/Canadian rap
-
Chinese/Country/Canadian rock
-
Turkish/Tunisian/Taiwanese rap
There hasn't been a single post this year!
(Happy 2022 from New Zealand)
Nothing, it just waved
Him: I can explain everything!
(It's his best joke yet I think)
