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Content Guidelinesplugin-autotooltip__plain plugin-autotooltip_bigContent guidelines

Ideas for new topics are always welcomed, from experts and non-experts alike - if you're not sure if they'll be accepted by other editors, put them in the 'proposed_content' section for approval. The easiest way to create a new page is to use the

Registrationplugin-autotooltip__plain plugin-autotooltip_bigRegistration

At present, only registered users can create and edit articles. The registration process is very straightforward. Just click the 'Register' link at the top right of any page.

After you've registered, you'll be able to login with your password at any time…

How to edit pagesplugin-autotooltip__plain plugin-autotooltip_bigEditing pages

Once you're logged in, a grey floating 'Tool' menu at the right hand side of the screen enables access to all the main 'Content Pages' for editing. (Note: Some pages, such as the site info etc. are locked)

Like most Wikis, the site doesn't use

Importance Ratingsplugin-autotooltip__plain plugin-autotooltip_bigImportance ratings

In a departure from the usual Wiki format, Wikenigma assigns 'Importance Ratings' to some the page pages.

The idea is to separate articles which are considered (by the editors) to cover exceptionally important unknown issues from those which (althou…

Faqplugin-autotooltip__plain plugin-autotooltip_bigFrequently Asked Questions

Q. Why the weird syntax? A. Like most Wikis, the site doesn't use HTML for formatting (security reasons etc). A guide to the special syntax can be found here. Unfortunately it can be quite confusing at first - but there's now a new 'Visual …

Newsplugin-autotooltip__plain plugin-autotooltip_bigNews

[ newest at the top ]

• Aug 2020 : Currently (beta) testing the new 'WYSIWYG' (What You See Is What You Get) page editor. It greatly simplifies the editing process, avoiding the need to learn the Wiki syntax. (Note: it's currently not 100% stable)

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Legalplugin-autotooltip__plain plugin-autotooltip_bigLegal

• Content in general

Please note that in common with other publicly editable wikis, this website is not responsible for content posted by the public. Nevertheless, the ongoing editing process should be able to remove unsuitable content in a reasonable time. If y…

492 unknowns listed

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plugin-autotooltip__plain plugin-autotooltip_bigDonate to Wikenigma . . .

The best way to donate is by adding new original content !

That can either be by contributing to an existing article, or by creating a new page with an as-yet-unlisted 'Known Unknown'.

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Wikenigma - an Encyclopedia of Unknowns Wikenigma - an Encyclopedia of the Unknown Wikenigma - an Encyclopaedia of Unknowns Wikenigma - an Encyclopaedia of the Unknown

The Oxygen Effect (radiology)

The Oxygen Effect refers to the discovery (made in 1921) that living cells are significantly more damaged by radiation (X-ray, particle beams etc) in the presence of oxygen.

It's currently of particular sigificance to radiologists, who want to preserve cells undamaged (e.g. X-rays) - or when deliberately trying to damage cells in tumour radiation etc. The presence of oxygen can increase the rate of damage by up to 300%.

There are several theories which attempt to explain the effect - but no general agreement as yet.

The best known explanation of the oxygen effect is the oxygen fixation hypothesis developed by Alexander in 1962, which posited that radiation-induced non-restorable or “fixed” nuclear DNA lesions are lethal to cells in the presence of diatomic oxygen. Recent hypotheses include one based on oxygen-enhanced damage from first principles.. Another hypothesis posits that ionizing radiation provokes mitochondria to produce reactive oxygen (and nitrogen species), which are leakage during oxidative phosphorylation that varies with a hyperbolic saturation relationship observed with both the oxygen and nitric oxide effects
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