Science desk
< February 8	<< Jan \| February \| Mar >>	February 10 >

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

February 9

How is Meclofenoxate produced?

Please provide info on how Meclofenoxate is produced. When taken as a drug or a supplement is the source generally plant or animal based; or is it primarily synthetically produced in a lab? And if the latter - what chemicals are used in Centrophenoxine production and where are those sourced from? Dkw1 (talk) 05:03, 9 February 2017 (UTC)dkw1[reply]

Both ;-) -- it's made from one natural substance, DMAE, and one synthetic substance, pCPA. 2601:646:8E01:7E0B:BDF1:AD7D:2270:53EB (talk) 05:17, 9 February 2017 (UTC)[reply]

Ah, I was late. Meclofenoxate is exclusively synthetic, as it is not found in nature [1] (the details of its invention are described in the article, Derives des acides regulateurs de croissante des vegetaux, I-Proprietes pharmacoligiques de l'ester dimethylaminoethylique de l'acide p-chlorophenoxy-acetique, 1959, which has sadly never been digitized). As the IP above said, one of the ingredients for making it, DMAE, is a naturally occuring compound. However, DMAE can also be made synthetically, and apparently, although meclofenoxate manufacturers love to tout that it is derived from a "natural" compound, most commercially supplied DMAE is synthetic[2], being made from a reaction of diethylamine and ethylene oxide. The ethylene oxide is synthetic, but as with DMAE, diethylamine can be either natural or synthetic. I haven't been able to figure out if commercial diethylamine is primarily synthetic or natural. This basically becomes a deep rabbit hole, looking for the ~~white~~ natural rabbit. The only way to know for sure is to contact the manufacturer of your choice, and ask them how their product is made, and where their source material comes from. They might not tell you. Someguy1221 (talk) 05:35, 9 February 2017 (UTC)[reply]

I'd like to restate/add some relevant links and background: Meclofenoxate is the ester of 4-chlorophenoxyacetic acid, which our article calls a "synthetic pesticide" resembling auxins, with dimethylethanolamine. Our article claims an anti-aging effect of 30-50% in mice, while backhandedly mentioning that the DMEA component has a similar effect - I haven't gone into this yet, but I'd expect an ester to be broken down during digestion, so I'd want to see if there's any reason to think the other half is relevant to this. One of the sources in the article [3] says it works by inhibiting lipofuscin production, which can be done with other chemicals; however, looking at a review it looks like another route that (more indirectly) blocked lipofuscin accumulation had no effect on advanced dry macular degeneration. [4] (The retina is the most readily observable part of the nervous system where lipofuscin accumulates). Lipofuscin toxicity triggers autophagy, which can be a good thing... [5] I assume it is possible that it is just a symptom and not a cause of trouble, but a lot of thinking is needed to sort everything out. Wnt (talk) 14:32, 9 February 2017 (UTC)[reply]

I removed the comments about the nature of DMEA and pCPA from the drug article because they are irrelevant and uncitedly insinuate something about the "natural" nature or biochemical effect of the commercial product. DMacks (talk) 16:36, 9 February 2017 (UTC)[reply]

@DMacks: I'm not sure it doesn't belong. It's irrelevant to the chemistry, but there are weird legal issues where something that can be nominally claimed as "naturally occurring" can then freely be synthesized and distributed as a chemical supplement. I don't really know the details though, and it is true it would be better to have an actual regulatory reference with appropriate language for that. Wnt (talk) 23:33, 9 February 2017 (UTC)[reply]

Yes, the problem is "uncitedly insinuate" about a reactant, not "citedly state about the product". DMacks (talk) 04:19, 10 February 2017 (UTC)[reply]

Question about the Physics

Since both "g" and "G" are time dependent therefore do the "g" and "G" of a moving object (if travels close to the speed of light) also dilate and change (i know about the change in mass) due to time dilation relative to other observers?2001:56A:7399:1200:C492:FEEE:13DC:82C7 (talk) 06:29, 9 February 2017 (UTC)EEK[reply]

Define "g" and "G". Are you talking about acceleration of gravity and gravitational constant? Someguy1221 (talk) 07:19, 9 February 2017 (UTC)[reply]

yes i am talking about Gravitational constant "G" and acceleration due to gravity "g".

This discussion at Stack Exchange seems to be relevant. --Jayron 32 14:08, 10 February 2017 (UTC)[reply]

Rabies virus detection in blood

According to rabies, "Rabies can be difficult to diagnose" because "after a typical human infection by bite [...] the virus cannot be easily detected within the host". CDC also says "Several tests are necessary... in humans; no single test is sufficient". Why the virus cannot be detected by blood sample, like HIV, etc (particularly before the symptoms become apparent)? Even if the virus is somehow invisible to microscopes, Rabies#Cause mentions some specific pathological changes (such as the release of five proteins and single strand RNA into the cytoplasm) through which the infection could be inferred. Not a request for medical help. Brandmeister^talk 18:12, 9 February 2017 (UTC)[reply]

Many viruses cannot be directly detected, instead what many tests look far are antibodies and antigens to the virus. It is quite possible to be infected (and also contagious) before antibodies themselves reach detectable levels. More modern tests have gotten MUCH better in recent years, such that viral RNA can now be directly tested for. This page covers testing protocols for Rabies, and notes that due to the low reliability of any individual test, multiple tests must be done. The only test which is known to be reliable enough is the Direct fluorescent antibody on the brain tissue of an infected person; for obvious reasons this is not often done on live patients. From what I can read at Rabies and these other articles, that is because the viral load in body fluids is relatively low, the virus tends to collect and concentrate in nerve tissue. --Jayron 32 18:55, 9 February 2017 (UTC)[reply]

I wouldn't be surprised if the viral load during the latent phase is zero or nearly zero. As I understand it, the virus works its way up the nerves till it gets to the brain. There was a case of an American soldier who broke up a dogfight in Afghanistan. They gave him the vaccine but it was expired (and possibly diluted?). He didn't show symptoms for eight months, by which point he was already back in the States. At that point there was nothing they could do (though admittedly I don't know what they tried).

That's from memory — does anyone have more details on the story? I could have some of it wrong. --Trovatore (talk) 19:05, 9 February 2017 (UTC)[reply]

CDC case report. Someguy1221 (talk) 20:33, 9 February 2017 (UTC)[reply]

Thanks for the find. What a grim story. --Trovatore (talk) 21:11, 9 February 2017 (UTC)[reply]

Here's a news story about it [6]. Apparently there's a general order against mascots, but it has been ignored ... and one of the 'base dogs' got into a fight with an outside dog, and this guy was bit trying to separate them. I am tempted to joke about ways a Nigerian soldier and a North Korean soldier would stop a dog fight... Wnt (talk) 23:41, 9 February 2017 (UTC)[reply]

"1A6" and "M1" in the context of machining

What's "1A6" and "M1" in the context of machining [7]? ECS LIVA Z (talk) 20:52, 9 February 2017 (UTC)[reply]

You may ask the company Vedos BV in Holland, contact details here. Blooteuth (talk) 02:23, 10 February 2017 (UTC)[reply]

Pedantic correction, the company you linked to is not in Holland. It's in the province of Limburg, the other end of the Netherlands from Holland. Fgf10 (talk) 07:51, 10 February 2017 (UTC)[reply]

The company address is given as Venlo, Nederland. I may have upset local feelings by equating Nederland with the country known by English speakers as Holland. On 9 November 1939 German SD agents arrested British agents in the Venlo Incident and the Nazi government later used the event to help justify Germany's invasion of neutral Holland. As far as I can tell, Venlo is neither in Germany nor in the Belgian part of Limburg which leaves its inhabitants free to cheer on the Holland football team. Blooteuth (talk) 18:54, 10 February 2017 (UTC)[reply]

This site explains why to say someone from Limburg is from Holland is considered an insult. While a published map of Holland[sic] adds the injury of misspelling VENLO, I apologise to all in The Kingdom of the Netherlands for my unwitting error. Blooteuth (talk) 20:36, 12 February 2017 (UTC)[reply]

"M1" is an ISO metric screw thread. I don't know about "1A6". Tigraan^{Click here to contact me} 08:32, 10 February 2017 (UTC)[reply]