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Chemistry in its element: End promo Chris Smith Hello, this week we turn to one of the most important elements in the human body. It's the one that makes metabolism possible and don't we just know it. There are iron man challenges, iron fisted leaders and those said to have iron in the soul. But there's a dark side to element number 26 too because its powerful chemistry means that it's also bad news for brain cells as Nobel Laureate Kary Mullis explains Kary Mullis For the human brain, iron is essential yet deadly.
This change from the relatively plentiful and soluble FeII, took a heavy toil on almost everything alive at the time. Surviving terrestrial and ocean-dwelling microbes developed soluble siderophore molecules to regain access to this plentiful, but otherwise inaccessible essential resource, which used hydroxamate or catechol chelating groups to bring the FeIII back into solution.
Eventually higher organisms including animals, evolved. And animals used the energy of oxygen recombining with the hydrocarbons and carbohydrates in plant life to enable motion. Iron was essential to this process.
But no animal, however, has been able to adequately deal, in the long run - meaning eighty year life spans - with the fact that iron is essential for the conversion of solar energy to movement, but is virtually insoluble in water at neutral pH, and, even worse, is toxic.
Systems have evolved to maintain iron in specific useful and safe configurations - enzymes which utilize its catalytic powers, or transferrins and haemosiderins, which move it around and store it. But these are not perfect. Sometimes iron atoms are misplaced, and there are no known systems to recapture iron that has precipitated inside of a cell.
In some tissues, cells overloaded with iron can be recycled or destroyed - but this doesn't work for neurons. Neurons sprout thousands of processes during their existence - reaching out to form networks of connections to other neurons.
During development of the adult human brain a large percentage of cells are completely eliminated, and some new ones are added. It is a learning process. But once an area of the brain is up and running, there is nothing that can be done biologically, if a large number of its cells stop working for any reason.
And the slow creep of precipitating iron over many decades is perhaps most often that reason. In less sophisticated tissues, like the liver, new stem cells can be activated, but in the brain, trained, structurally complex, interconnected neurons are needed, with thousands of projections that are accumulated over a lifetime of learning.
So the result is slowly progressive neurodegenerative disease, like Parkinson's and Alzheimer's. This same basic mechanism can result in a variety of diseases. · The effects of synthesis method on the physical and chemical properties of dextran coated iron oxide nanoparticles Anastasia K.
Hauser, Ronita Mathias, Kimberly W. Anderson, and J. Zach Hilt * Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY alphabetnyc.com://alphabetnyc.com · iron - Physical and Chemical Properties - Iron, like other metals, conducts heat and electricity, has a luster, and forms positive ions in its chemical reactions.
Pure iron is fairly soft and can easily be shaped and formed when alphabetnyc.com://alphabetnyc.com · 0 Thermo - Physical Properties of Iron - Magnesium Alloys Krisztina K adas´ 1,2, Hualei Zhang 1,Borje Johansson¨ 1,3, Levente Vitos 1,2,3 and Rajeev Ahuja 1,2 1 KTH Royal Institute of Technology 2 Research Institute for Solid State Physics and Optics 3 Uppsala University 1,3 Sweden 2 Hungary 1.
Introduction According to the common phase diagrams, iron and magnesium are almost alphabetnyc.com · (2) The physical properties of Muko iron ores meet the feed natural material requirements for the blast furnace and different methods for direct reduction of iron (Midrex, HYL III, and SL/RN).
Only samples Ug1, -2, and -6 fall short of meeting the HYL III alphabetnyc.com://alphabetnyc.com · Physical properties are attributes of a substance that can be observed or measured without changing the composition (molecular structure) of the substance.
Examples of physical properties include alphabetnyc.com · Physical properties; Phase at However, the mechanical properties of iron are significantly affected by the sample's purity: pure, single crystals of iron are actually softer than aluminium, and the purest industrially produced iron (%) has a hardness of 20–30 alphabetnyc.com://alphabetnyc.com