• WordNet 3.6
    • n urea the chief solid component of mammalian urine; synthesized from ammonia and carbon dioxide and used as fertilizer and in animal feed and in plastics
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Webster's Revised Unabridged Dictionary
    • a Urea (Physiol. Chem) A very soluble crystalline body which is the chief constituent of the urine in mammals and some other animals. It is also present in small quantity in blood, serous fluids, lymph, the liver, etc.☞ It is the main product of the regressive metamorphosis (katabolism) of proteid matter in the body, and is excreted daily to the amount of about 500 grains by a man of average weight. Chemically it is carbamide, CO(NH2)2, and when heated with strong acids or alkalies is decomposed into carbonic acid and ammonia. It unites with acids to form salts, as nitrate of urea, and it can be made synthetically from ammonium cyanate, with which it is isomeric.
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Century Dictionary and Cyclopedia
    • n urea It is the most important nitrogenous waste product of the mammalian organism. It is an acid amide, its solutions presenting a neutral reaction. It can combine with acids to form crystalline, salt-like products, and is decomposed by sodium hypobromite and the hypochlorite with the liberation of carbon dioxid, nitrogen, and water. On heating the substance ammonia is given off and biuret formed.
    • n urea Carbamide, CO.(NH2)2, a crystalline solid, soluble in water, and forming crystalline compounds with both acids and bases. It is the final product of the proteid decomposition in the body, and forms the chief solid constituent of the urine of mammals. It appears also in the urine of birds.
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Chambers's Twentieth Century Dictionary
    • n Urea ū′rē-a a readily soluble colourless crystalline compound formed in the tissues during the disintegration of proteid material, and carried by the blood to the kidneys, which separate it and pass it off in the urine
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Webster's Revised Unabridged Dictionary
NL. See Urine
Chambers's Twentieth Century Dictionary
Gr. ouron, urine.


In literature:

This remedy was thought to convert uric acid into urea, and to so help elimination.
"Scientific American Supplement No. 299" by Various
The urea and uric acids represent the final result of the breaking down in the body of nitrogenous substances, of which albumen is the type.
"A Practical Physiology" by Albert F. Blaisdell
The fluid dropping from the ureter contained more urea than did the blood.
"Scientific American Supplement, No. 586, March 26, 1887" by Various
The seizing of the urea by the kidney cell is a vital phenomenon which we must waive for the moment.
"The Story of the Living Machine" by H. W. Conn
In that case it is necessary to add an antacid such as urea to prevent its getting yellow or opaque.
"Creative Chemistry" by Edwin E. Slosson
This quantity usually holds in solution about one ounce of urea, and ten or twelve grains of uric acid.
"The People's Common Sense Medical Adviser in Plain English" by R. V. Pierce
The water of the urine is probably filtered off in the capsule, the urea and other salts secreted by the tubuli.
"Text Book of Biology, Part 1: Vertebrata" by H. G. Wells
At any rate, as the plants were not tested for urea, the experiments must be regarded as leaving the problem unsolved.
"Manures and the principles of manuring" by Charles Morton Aikman
UREA, secretion of, ii.
"The Variation of Animals and Plants Under Domestication, Volume II (of 2)" by Charles Darwin
The common source of ammonia in such cases is from decomposition of the urea in fermenting urine.
"Special Report on Diseases of Cattle" by U.S. Department of Agriculture

In news:

We are facing problem in a urea HP condenser .
Introduces a new range of FSC-certified PlybooStrand bamboo plywood and flooring FSC PlybooStrand plywood and flooring are both urea formaldehyde-free, earning the line Indoor Advantage Gold and FloorScore certifications.
BioNitrogen has signed a three-year agreement with PRM Energy System to construct the gasification units for its urea plants.
Ucyclyd sells rights to urea cycle disorder treatment Ravicti.
P amplona is chef-owner Alex Ureña's bow to reality.
Ureña, his passionate celebration of molecular cooking in this same modest space, didn't pay the bills.
As a delivery device for urea, lotion is much more effective than pee .
Free sample urea price report.
Get the most comprehensive and accurate urea price assessments.
Products Provide Urea Without The Loss, Expert Says.
AGROTAIN International, a leading producer of Stabilized Nitrogen fertilizers, has launched its Urea Center showcase website, www.
Liquid Crystals in O/W Emulsions with Urea : Development and Testing CosmeticsAndToiletries.com.
Ask your doctor for the urea test.
China's urea production is expected to increase in 2012, exceeding growth in downstream demand, with producers to face stiff competition amid a weak supply demand outlook.
However, Nelson's fertilizers actually included large amounts of synthetic materials including aqueous ammonia, ammonium sulfate, and urea.

In science:

In vitro, the transition between the various phases is controlled by temperature, pH, denaturant agent (such as urea or guanidine).
Protein folding and heteropolymers
A) of the N−C bond in the urea moiety (ℓ3 in Fig. 3), CF the Flory characteristic ratio, ξe the effective bond number defined earlier , and x the number of repeating units.
Theory of Gel Formation
There is little information about the expansion factor of poly(urea).
Theory of Gel Formation
Hence, in the system cited above , the poly(urea) formation must always be accompanied by the urethane bond formation that wastes FU’s because of the use of isopropyl alcohol as the reaction solvent.
Theory of Gel Formation
Two-Dimensional Electrophoretic Analysis of BasicProteins Using Phosphatidyl Choline Urea Solubilization.
Improved proteomic analysis of nuclear proteins, as exemplified by the comparison of two myelo\"id cell lines nuclear proteomes