Wikipedia:Reference desk/Archives/Science/2014 December 23

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December 23

Why insulin is not taken oral but in injection?

5.28.180.110 (talk) 12:20, 23 December 2014 (UTC)

It would be destoyed by digestion. Roger (Dodger67) (talk) 14:00, 23 December 2014 (UTC)

Yes, as described at the end of Insulin#Medication uses:

Unlike many medicines, insulin currently cannot be taken orally because, like nearly all other proteins introduced into the gastrointestinal tract, it is reduced to fragments (even single amino acid components), whereupon all activity is lost. There has been some research into ways to protect insulin from the digestive tract, so that it can be administered orally or sublingually. While experimental, several companies now have various formulations in human clinical trials, and one, the India-based Biocon, has formed an agreement with BMS to produce an oral-insulin alternative.

The questioner may also wish to read anti-diabetic medication, which mentions many drugs, such as the commonly prescribed metformin, which can be taken orally. -- ToE 14:03, 23 December 2014 (UTC)

Isn't "anti-diabetes medication" a better term ? "Anti-diabetic medication" sounds like it's designed to eliminate diabetics, not treat diabetes. StuRat (talk) 16:18, 23 December 2014 (UTC)

Yes, it sounds like a candidate for a move. ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:28, 23 December 2014 (UTC)

While both terms are used in the literature, anti-diabetic appears to be used much more commonly than anti-diabetes. -- ToE 22:25, 23 December 2014 (UTC)

The problem is that people with diabetes are called "diabetics", so "anti-diabetic" can mean "against people with diabetics". StuRat (talk) 00:19, 24 December 2014 (UTC)

It could. And yet it doesn't. There's no reason to deviate from standard terminology. - Nunh-huh 00:48, 24 December 2014 (UTC)

The problem is that "diabetic" is an adjective which has been co-opted as shorthand for "people with diabetes". ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:33, 24 December 2014 (UTC)

I don't think it deviates either. You would have "anti-cancer medication" not "anti-carcinogenic medicine", which, again, would mean something else. StuRat (talk) 05:21, 24 December 2014 (UTC)

The problem is that the term "diabetic" is an adjective which means "about diabetes". The term "anti-diabetic" drugs does seem to be at odds with other medical "anti-" terms which are more likely to be nouns, like maybe "anti-cancer" drugs. Although there are also terms like "anti-inflammatory", which is also an adjective. ←Baseball Bugs ^{What's up, Doc?} carrots→ 15:10, 24 December 2014 (UTC)

This is only a problem in your mind. Many words in English can be either a noun or an adjective depending on context. --65.94.50.4 (talk) 00:59, 25 December 2014 (UTC)

Custom books on water- and tear- resistant paper

I've seen pocket-size reference books printed on paper that's water-resistant. I think the paper is tear-resistant too but I'm less certain about that. Can you print custom books inexpensively in very small quantities (1 or several) on that kind of paper? I've seen notebooks made of rain-resistant paper, but you will have to write the content with a pen; that's not what I'm looking for. --173.49.11.192 (talk) 15:19, 23 December 2014 (UTC)

Regular printers can handle overhead projection slides, which are certainly waterproof, and I imagine an opaque version can be made. However, the ink is another issue, with ink-jet printer ink being water soluble. I think laser jet toner may hold up better to water. StuRat (talk) 16:14, 23 December 2014 (UTC)

I've had success using a laser cutter to etch text onto all sorts of materials. The marks it makes are essentially impossible to remove by any means - and most materials can be etched (albeit with some difficulty). But it would be time-consuming to make a book with a lot of text in it that way. I guess you'd have to contact businesses like CafePress who specialize in on-demand printing. SteveBaker (talk) 17:27, 23 December 2014 (UTC)

On the 'Net, I found "weatherproof paper" made by a company called iGage. The product seems to be for print custom maps for outdoor activities and seems to be made of a tough material. It's supposed to work with some inkject and laser printers. The downside to it is that it's very expensive—something like 75¢ per sheet! If someone knows of a cheaper/better solution, please share the info. Thanks. --173.49.11.192 (talk) 18:03, 23 December 2014 (UTC)

Vellum (the plasticized cotton version) is what's used for blueprints, so that can be taken to job sites and not dissolve in the rain. It seems to cost about 15¢ per sheet: [1]. Some of their products contain warnings not to use them in a normal printer: [2], but others do not. You might want to contact them and ask specifically which will work in a given printer. StuRat (talk) 18:23, 23 December 2014 (UTC)

I've used Aquascribe paper before to photocopy detailed maps for geological mapping - you could write under water with that stuff and it was tear-resistant. Here's the website - £33.80 (so about $22) about for 250 A4 sheets, more expensive of course in smaller quantities. Mikenorton (talk) 20:38, 23 December 2014 (UTC)

The currency markets have been a bit crazy recently with Russia, but not that crazy. Apparently it's roughly 1.55 USD per pound sterling, so $52 or so, so that would be 21 cents a sheet. Wnt (talk) 21:24, 23 December 2014 (UTC)

Oops, should have multiplied rather than dividing by 1.55, just as well I don't work in finance. Mikenorton (talk) 23:29, 23 December 2014 (UTC)

I've also seen books for toddlers made to be waterproof, so they don't have to be thrown out the first time a lollipop ends up stuck to a page. StuRat (talk) 00:36, 24 December 2014 (UTC)

Is it dangerous to drink pure water (H2O)?

If so, what is the amount that can make damage? (it can help for example for someone who has only air conditioner or for someone in the desert - by collecting the water from the air) 5.28.180.110 (talk) 15:42, 23 December 2014 (UTC)

This WHO report explores the issues with drinking demineralised water - the lack of magnesium and calcium are the main potential problems, although this is with long term use. Mikenorton (talk) 16:07, 23 December 2014 (UTC)

And note that condensate is not pure water by any means. All the dust in the air tends to stick to the droplets that form, making it quite full of minerals, bacteria, etc. So, whether drinking condensate water is OK is another question. I should think that the longer the condensate sits, the more the bacteria in it would grow. StuRat (talk) 16:10, 23 December 2014 (UTC)

Distilled water seems to be about the closest you can get to "pure" water. As noted above, you probably don't want to consume it as a long term standard, but if you're desperate for water, it's better than nothing. The lack of minerals in it makes it very bland-tasting. One of the episodes of Going Deep With David Rees was about water, and he commented on that. ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:26, 23 December 2014 (UTC)

Well, you can make your water directly from Hydrogen and Oxygen...Naraht (talk) 15:20, 24 December 2014 (UTC)

Water intoxication sets an upper limit of around 0.8 liters per hour for short-term consumption (assuming an otherwise healthy person, etc, etc) - but that applies to all water, not just the super-pure stuff - and I don't think that's the scenario you're concerned about. Drinking water without the usual minerals in it isn't going to cause problems in the very short term - and it can only cause longer-term problems if you don't have sufficient of those minerals in your diet from someplace else. So the answer to this question is complicated - it depends on what food you eat and for how long you drink the stuff.

That said, the WHO report (linked to above) says that demineralized water tends to pick up more impurities (eg from the containers it's stored in) than mineralized water - so there could be an issue if this water is stored inappropriately.

SteveBaker (talk) 17:20, 23 December 2014 (UTC)

I thought drinking of distilled water can causes to hypocalemia and hyponatrmia, because its low density. 5.28.175.146 (talk) 02:20, 24 December 2014 (UTC)

Not if you are also eating food. You need calcium and sodium from anywhere - it doesn't have to be water. Ariel. (talk) 06:23, 24 December 2014 (UTC)

Semiconductor plants create some of the purest water. It is not considered drinkable because the osmotic pressure tends to create cells that have too much water. It can also leach calcium and other minerals from bones. that said, it wouldn't take much food to render it potable with no ill side-effects. --DHeyward (talk) 08:20, 26 December 2014 (UTC)

Diving with TLB technology

Supposing that Total Liquid Breathing (TLB) technology is used in diving, what is the highest pressure that the human body can endure, while maintaining consciousness? Plasmic Physics (talk) 23:22, 23 December 2014 (UTC)

The deeper one dives the more readily the calcium in one's bones dissolve. So 'perhaps' one could remain conscious at the depths deep enough to reduce one to a blob of jelly. In the advancement of science -do we have a volunteer here?--Aspro (talk) 00:23, 24 December 2014 (UTC)

As we share 90% of our DNA with fish, maybe the limiting factor is the efficiency of our enzymes at depth. The Biology of the Deep Ocean By Peter Herring Think we need a volunteer to discover that point. With nitrogen psychosis, some divers can cope at depths below which others succumb to it. So survival may be possible for days with with TLB or just minutes, depending on the individual but we wont know until someone volunteers themselves in the name of science.--Aspro (talk) 00:59, 24 December 2014 (UTC)

Our article on liquid breathing cites a surprisingly high 10 liter per minute rate for fluid exchange using the current liquids. It's amazing that an animal with lungs can breathe any liquid, but to use it in diving it sounds like they need a better liquid than what they have.

FWIW, I'm gonna guess graphene. (To trap gas in a compressed state in perfluoro solution) You can do anything with graphene, if you could do anything with graphene! Wnt (talk) 01:56, 24 December 2014 (UTC)

These are technological challenges that lies beyond the scope of this query. Plasmic Physics (talk) 08:56, 24 December 2014 (UTC)

Yes, I do think that is a limiting factor, but is it the limiting factor? Plasmic Physics (talk) 08:56, 24 December 2014 (UTC)