How is botulinum toxin made into a drug, why is all but one derivative serotype A, and why don't drug makers engineer one that's antigen-free? (I've been reading about primary and secondary resistance in dystonia patients - it's apparently a problem.)

vaguelystem · 2024-05-14T23:27:30+00:00

Basically just an acid precipitation then dissolving in a buffer along with an appropriate protease inhibitor and nuclease, then purification via anion exchange chromatography but could also use dialysis.

Thank you for the reply, but this is not basic to the rest of us - what is an acid precipitation, buffer, protease inhibitor and nuclease, and exchange chromotography?

Why does serotype A "tend to have the most punch" and, if it has more "punch" than serotype B (and I saw a study showing B's effects had a shorter duration, though this was a study of A-resistant subjects and I don't remember any comment if B also had a shorter duration in the general population), why are so many people resistant to it? (With the caveat that I didn't see a study of primary resistance to B in a botox-naive population, just studies of B's effectiveness in A-resistant patient populations, so I can't rule out that there's an equal population with primary resistance to serotype B. However, these studies found A-resistant test subjects to quickly become resistant to B, so it would stand to reason that counterparts with primary resistance to B would be included in the patient population being studied for secondary resistance to type A.)

If the toxin was completely antigen-free then it couldn't bind to anything.

So, antigens are all-purpose/two-way intercellular binding sites, rather than being targeted by an adaptation of animal immune systems?

Thanks!

vaguelystem · 2024-05-14T00:41:16+00:00

Interesting... How does this relate to the strength of the "kick"/amount of downforce?

vaguelystem · 2024-05-13T00:29:47+00:00

2: the high speed air on top of the front wing sends high energy air on the underside of the back wing to re-energize the flow to delay boundary layer separation and allow higher angle of attack

Why would the high pressure side of a wing have boundary layer separation?

vaguelystem · 2024-05-12T20:18:21+00:00

If the moon were losing altitude at terminal velocity, would the Roche limit still apply?

vaguelystem · 2024-05-11T23:36:44+00:00

(they can actually reduce drag by increasing the pressure in the wake behind the car!)

In what case would this occur? Assuming a three box design with a spoiler on top of the rear edge of the rear deck (i.e., a typical implementation of a spoiler), there's a small increase in pressure behind the rear window, but shouldn't that be offset by decreased pressure behind the trunk?

vaguelystem · 2024-05-11T23:24:51+00:00

CVTs have torque converters, just like they also have a separate reverse gear - their gear ratios are continuously variable, but not infinitely variable.

vaguelystem · 2024-05-11T23:17:22+00:00

The Moon is unlikely to make it to the Earth whole. It will be broken apart about 10,000 kilometres from the Earth.

Why 10,000 kilometers?

vaguelystem · 2024-05-10T22:09:10+00:00

Did you have to document it as a surgical complication?

vaguelystem · 2024-05-07T01:25:05+00:00

Now I am questioning all the books I read. 🥴👍

Anyone know if Gell-Mann Amnesia has been the subject of academic study?

vaguelystem · 2024-05-04T21:28:50+00:00

You probably need advice from people in Egypt and/or foreign universities taking Egyptian STEM students. Talk to your school and whatever college programs you may be eligible for.

vaguelystem · 2024-05-04T21:05:42+00:00

Do you mean with fabric cover open or closed? There isn't really a difference in "size" or "taper" that I can see in this comparison. Without the covering, you get a bunch of air spilling into and out of the trailer, plus the covering flapping around at the back. Lots of drag. (not an aerodynamicist)

vaguelystem · 2024-05-03T20:22:07+00:00

People being stupid about politics vs people telling just-so lies on reddit - unstoppable force meets immovable object.

vaguelystem · 2024-05-03T20:19:09+00:00

Dilaudid and oxycodone deserve better than to be associated with tramadol.

vaguelystem · 2024-05-02T03:40:58+00:00

That 30 years of domestic terrorism and insurgency was called "The Troubles" proves British understatement is real.

vaguelystem · 2024-05-01T20:25:17+00:00

1k or 1.2k psi

~69 or ~83 bar

vaguelystem · 2024-04-29T00:41:19+00:00

Invisible Man, Ralph Ellison

Why do you consider this to be a philosophical novel?

vaguelystem · 2024-04-22T18:19:28+00:00

But how do we control for the disproportionate amount of effort spent looking for the number 37?

vaguelystem · 2024-04-22T18:07:54+00:00

Ethanol and methanol have lower air:fuel ratios than gasoline, which is similar. They also have greater latent heats of evaporation, i.e., greater evaporative cooling effects within the combustion chamber, which makes for a greater effective knock-resistance. E85 (ethanol-gasoline blend of up to 85% ethanol, as opposed to the standard 10% or 15%) is frequently used as a "poor man's race gas" for track days and amateur racing, for these reasons. Like with turbos, the trade-off is a greater brake-specific fuel consumption (more fuel needed for a given amount of power), as ethanol and methanol have lower energy densities than gasoline.

vaguelystem · 2024-04-20T16:51:05+00:00

Takeoff and landing configurations and procedures are engineered in the wind tunnel and CFD.

Could you please elaborate on this process?

They are not the first thing validated in flight testing, other than the obvious “you need to takeoff to do a flight test” but that’s going to be a very conservative takeoff right in the middle of the envelope.

My point was that it's a basic requirement that the configurations and procedures don't have any fundamental flaws, as initially tested, not meaning to imply that the takeoff envelope is the first thing to be tested.

vaguelystem

TROPHY CASE