Also why you don't re-use needles:

Also why you don't re-use needles:

That's not the main reason why we don't reuse needles.
For even into the same patient…
Pfft I reckon we can reuse it once from that pic
Or from draw into injection
Insulin needles are used in this way, because they're usually permanently attached to their syringe. Rather than using a drawing needle then an injection needle.
Oh does insulin have a thick rubber stopper? I'm a lemmy stereotype and so my only experience with injections is estrogen
It's a little misleading in that the last photo is zoomed in a lot more than the previous ones. This one has that without the extra zoom in.

Could they be cleaned with isopropyl alcohol or an autoclave?
It's less about the dirt than the tip deforming.
When the needle is less pointy, it'll hurt more.
Not only that but look how it forms a freaking fishing hook on the end like a barb. Yikes!!!
Autoclave will deform the needle even more. The edge of the tip is made from softer steel so that it is sharper while at the same time more deformable.
Assumably also for manufacturing and safety reasons. You don't want the tip of a needle to shatter inside you, softer steel won't do that. And it's a little bit easier to manufacture with softer steel as well.
Needles were autoclaved and re-used once upon a time, so it should be possible. But disposable needles are probably made of softer material than reusable ones.
Those were made up harder steel which can't be sharpened to the degree softer steel can be. Harder steel shatters if sharpened since harder it is brittle it becomes.
So reusable needle are blunt, so injections are painful. And as mentioned by @Natanox@discuss.tchncs.de they used to shatter inside the body after a few cycles of autoclaving.
Wow, I did not expect that.
Can we see the skin after that sixth use?

To shreds, you say.
There was missing something...



Hard to believe. To prepare a sample for an electron microscope you need to freeze it to nitrogen temperatures or below. You can fix it using glutaraldehyde, but again, you need to cut it accurately immediately after the penetration. My bet is that either stabbed dead skin or some sort of graphics.
Yes! When I did electron microscopy, we had to cover the fix the samples and cover them with a very thin gold layer beforehand.
Yeah, and it's impossible to catch color!
In rationalist hell there is a special teapot for people who color SEM images
Thanks, I hate it. Not because of the hole, but because of how unhealthy the skin looks in this picture.
Were you expecting it to be smooth like plastic? The top layer is basically a bunch of dead skin cells that keep flaking away from the top layer and building up again from the lower layers.
Not if you moisturize
^/s,^ ^of^ ^course,^ ^though^ ^I’m^ ^sure^ ^you^ ^could^ ^put^ ^this^ ^photo^ ^on^ ^Instagram^ ^and^ ^be^ ^like^ ^“this^ ^is^ ^your^ ^skin^ ^without^ ^my^ ^brand^ ^of^ ^healing^ ^lotion^ ^made^ ^of^ ^baby^ ^foreskin”^ ^and^ ^make^ ^plenty^ ^of^ ^sales^

dehydrate dehydrate dehydrate...
Scanning electron microscopes image in a vacuum. Nothing looks 100% like it does at sea level when you suck all the air out.
Most SEMs use a vacuum chamber to get their photos. Also, it's not uncommon to sputter a conductive coating onto the surface you're scanning.
How the hell did they get this photo?
Environmental SEMs do not require vacuum and can be used for nonconductive samples. The beam ionizes the air which prevents the sample from charging. Magnification is limited but it is more than enough for this.
You can tell it is SEM and not optical by the depth of field. An optical image at this magnification would have much less DoF so the peaks/valleys would be blurry.
Put a needle in someone, freeze them solid with liquid nitrogen, then take a picture. Throw body out with rest of specimens.
Easy peasy.
It likely wasn't done on an electron microscope, or at least there is no reason to. There is no scale bar, but quick look online tells me a very fine needle is about 0.016in. 500x magnification optical lens would give you more than enough resolution for a photo like that.
I'm more intrigued by the fact there's no blood, they must've taken this milliseconds after the needle was removed? Or it's a dead body.
no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no no
Yes ( ͡° ͜ʖ ͡°)

The pores on my face as seen by the naked eye.
Everything reminds me of her
Just about everything can seem big when you have an electron microscope
I should also call your mom.
Wonder what it looks like after I scratch it for 50 minutes straight because my pain receptors are bad and I won't stop till I see blood.
It also happens to be just big enough for Trump his penis.
Skin kinda looks like dried up paint (I don't paint). Is this dryer than normal, or?
Apparently electron microscopes work in a vacuum. So this is a needle hole in skin, in a vacuum.
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