Urea sentence example

urea
  • When heated with urea, it forms oxalyl diureide, H 2 N [[Coco.
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  • phys [2], 8, p. 235) concentrates the urine and precipitates the urea by nitric acid.
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  • The urea oxalate is recrystallized and decolorized and finally decomposed by calcium carbonate (J.
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  • Alkaline hypobromites or hypochlorites or nitrous acid decompose urea into carbon dioxide and nitrogen.
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  • Dry chlorine gas passed into melted urea decomposes it with formation of cyanuric acid and ammonium chloride, nitrogen and ammonia being simultaneously liberated.
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  • Potassium permanganate oxidizes it to urea (R.
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  • On oxidation with potassium permanganate it is converted into acetyl urea, together with other products.
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  • On the latter they act as diuretics, but less powerfully than potassium, increasing the flow of water and the output of urea and rendering the urine less acid.
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  • Ethyl nitrate, C2H5.0N02, is a colourless liquid which boils at 86.3° C. It is prepared by the action of nitric acid on ethyl alcohol (some urea being added to the nitric acid, in order to destroy any nitrous acid that might be produced in secondary reactions and which, if not removed, would cause explosive decomposition of the ethyl nitrate).
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  • Urea may be recognized by its crystalline oxalate and nitrate, which are produced on adding oxalic and nitric acids to concentrated solutions of the base; by the white precipitate formed on adding mercuric nitrate to the neutral aqueous solutions of urea; and by the so-called "biuret" reaction.
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  • For example, aa-dimethyl urea is sweet, aß-dimethyl urea is tasteless; p-phenetol carbamide or dulcin, NH 2 CO NH C 6 H 4.0C 2 H 51 is sweet, while the di-p-phenetol carbamide, CO(NH C 6 H 4.0C 2 H 5) 21 is tasteless.
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  • The derivatives of urea containing acid radicles are known as ureides.
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  • Those derived from monobasic acids, obtained by the action of acid chlorides or anhydrides on urea, decompose on heating and do not form salts.
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  • Acetyl urea, NH 2 CO NH 000H 31 formed by the action of acetic anhydride on urea, crystallizes in needles which melt at 212° C. and, on heating, strongly decomposes into acetamide and cyanuric acid.
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  • Parabanic acid (oxalyl urea), C0[NH C0] 21 is formed by oxidizing uric acid; or by condensing oxalic acid and urea in the presence of phosphorus oxychloride.
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  • Tartronyl urea (dialuric acid), C0[NH CO]CH OH, formed by the reduction of alloxan (J.
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  • Allophanic acid, NH 2 C0 NH CO 2 H, is not known in the free state, as when liberated from its salts, it is decomposed into urea and carbon dioxide.
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  • Schiff, Ann., 1896, 291, p. 367); and by the action of urethanes on urea chloride (L.
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  • Biuret (allophanamide), NH 2 CO NH CO NH 2, is formed by heating urea; by the action of ammonia on allophanic ester; and by heating urea to 140° C. and passing chlorine into the melt at 140-150° C. (J.
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  • Grimaux by heating one part of glyoxylic acid with two parts of urea for ten hours at ioo° C.: 2CO(NH 2) 2 + CH(OH) 2 Oooh = 3h 2 O + C4H6N403.
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  • They show all the reactions of esters, being readily hydrolysed by caustic alkalis, and reacting with ammonia to produce carhamic esters and urea.
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  • Several methods are employed for the quantitative estimation of urea.
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  • Bromural or a-bromisovaleryl urea, NH 2 C0 NH C0 CHBr CH(CH 3) 2, has been introduced as an hypnotic; its action is mild, and interfered with by the presence of pain, cough or delirium.
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  • Hydrochloric acid at 200° C. decomposes into oxalic acid, carbon dioxide and methylamine, whilst an alcoholic solution of a caustic alkali gives dimethyl urea and oxalic acid.
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  • Veronal (q.v.) is diethyl malonyl urea.
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  • Baryta water hydrolyses it to carbon dioxide, ammonia and urea.
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  • Baryta water hydrolyses it to urea.
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  • By fusing guanidine with urea, dicyandiamidineH 2 N (HN): C NH CO NH 21 is formed.
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  • In health most of the nitrogenous waste in the body is eliminated as urea, but in gout uric acid is either formed in too great quantity or too little is eliminated, so that it tends to be deposited as urate of soda in the joints and other tissues.
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  • In 1862 Pasteur placed it beyond reasonable doubt that the ammoniacal fermentation of urea is due to the action of a minute Schizomycete; in 1864 this was confirmed by van Tieghem, and in 1874 by Cohn, who named the organism Micrococcus ureae.
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  • In effect the urea first becomes carbonate of ammonia by a simple hydrolysis brought about by bacteria, more and more definitely known since Pasteur, van Tieghem and Cohn first described them.
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  • The excreta of urea alone thus afford to the soil enormous stores of nitrogen combined in a form which can be rendered available by bacteria, and there are in addition the supplies brought down in rain from the atmosphere, and those due to other living debris.
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  • As regards the ammonium carbonate accumulating in the soil from the conversion of urea and other sources, we know from Winogradsky's researches that it undergoes oxidation in two stages owing to the activity of the so-called " nitrifying " bacteria (an unfortunate term inasmuch as " nitrification " refers merely to a particular phase of the cycle of changes undergone by nitrogen).
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  • It has been suggested that urea is formed by polymerization of ammonium carbonate, and formic aldehyde is synthesized from CO 2 and 011 2.
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  • The combined nitrogen of dead organisms, broken down to ammonia by putrefactive bacteria, the ammonia of urea and the results of the fixation of free nitrogen, together with traces of nitrogen salts due to meteoric activity, are thus seen to undergo various vicissitudes in the soil, rivers and surface of the globe generally.
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  • The amount of urea, creatin, creatinin, sulphates and phosphates in the urine is diminished, clearly showing that quinine exerts an inhibitory influence over the metabolic processes of the body.
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  • (saloquinine); and of the soluble substitutes, quinopyrine (a compound of quinine hydrochloride and antipyrine) and quinine hydrochlorocarbamide (a compound of quinine, urea and hydrochloric acid).
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  • Kinetic methods which measure the clearances (removal) of urea and creatinine are now the gold standard for the assessment of dialysis adequacy.
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  • Usually the pH is made more alkaline by hydrolysis of urea (NH 2 CONH 2) in boiling aqueous solution.
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  • The liver converts this ammonia to urea which is then excreted by the kidneys.
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  • ammonium chloride solution he obtained a white crystalline material which proved identical to urea obtained from urine.
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  • bicarbonate level decreased, blood urea nitrogen level increased and there was an increase in urinary calcium excretion.
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  • Stool antigen tests do not require a separate appointment at the practice and are cheaper than carbon urea breath testing.
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  • Urea is used as a top dressing in Portugal, mainly calcareous soils.
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  • In 1870 urea was produced by heating ammonium carbamate in a sealed vessel.
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  • Serum urea and electrolytes and creatinine to assess renal function (but a normal serum creatinine does not rule out obstruction ).
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  • creatinine levels High urea How many grams of fat is low fat?
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  • MDF MDF is largely composed of softwood bound together usually with a urea formaldehyde resin.
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  • Urease breaks down urea to form ammonia and free hydrogen ions which raise the pH of the urine making it alkaline.
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  • Urea is a relatively inert substance compared with ammonia.
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  • Urea is the main form in which nitrogen is excreted in mammals UV radiation invisible rays that are part of the electromagnetic spectrum.
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  • This minimizes the loss of urea from the renal medulla, and allows the concentration of urea in urine.
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  • methylene urea.
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  • For example, blood glucose levels in a diabetic dog or blood urea nitrogen levels for a cat with renal disease.
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  • They also assist saprophytes by excreting useful minerals such as urea, and by aerating the soil.
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  • In addition, the cleavage of arginine by nitric oxide synthetase generates citrulline, which is a urea cycle intermediate.
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  • Urography Care should be exercised in patients with moderate to severe impairment of renal function (as reflected by a raised blood urea ).
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  • The cream is an intense formula containing urea, which is the body's natural moisturizer.
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  • The same applies for thermal insulation materials which use urea and formaldehyde.
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  • Modern stain removers use artificially produced urea to achieve the same result.
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  • However, the kidneys are continuously removing urea from the blood and producing urine as a result.
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  • The greater the protein breakdown, the more urea is created and therefore more water is required for dilution.
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  • Certain metabolic products (e.g. urea) in excess can cause tissue damage.
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  • Excess non-protein nitrogen in the form of dietary urea reduced embryo quality.
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  • The urease splits urinary urea into ammonia and carbon dioxide, which results in phosphates and carbon in the urine.
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  • urea formaldehyde resin.
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  • urea nitrogen levels for a cat with renal disease.
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  • urea breath test.
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  • urea cycle.
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  • urea inclusion compounds studied, the optimum c g is ca.
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  • These changes result in an increase of about 50% in creatinine clearance, and a fall in serum urea, creatinine and urate.
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  • The dialysis disequilibrium syndrome is associated with rapid initial reduction in plasma urea levels at the commencement of dialysis.
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  • urea in the blood is excreted, along with a varying amount of water.
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  • The test is based on the capacity of H. pylori to secrete the enzyme urease, which hydrolyses urea to ammonia and carbon dioxide.
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  • Grimaux by heating one part of glyoxylic acid with two parts of urea for ten hours at ioo° C.: 2CO(NH 2) 2 + CH(OH) 2 Oooh = 3h 2 O + C4H6N403.
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  • On heating with water it undergoes hydrolysis into urea and allanturic acid C 3 H 4 O 3 N 2.
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  • It is reduced by sodium amalgam to glycouril C 4 H 6 N 4 O 2, whilst with hydriodic acid it yields urea and hydantoin C 3 H 4 N 2 O 2.
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  • The dihydro derivatives are most probably those compounds which are formed in the condensation of acidyl derivatives of acetone, with urea, guanidine, &c. Tetrahydropyrimidines are obtained by the action of amidines on trimethylene bromide: Br(CH 2) 3 Br+C 6 H 5 C (:NH) NH 2 = 2HBr+C 4 H 7 N 2 (C 6 H 5) [2].
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  • Uracil and its homologues may be obtained in many cases from the hydrouracils by the action of bromine, and subsequent elimination of the elements of hydrobromic acid; or by the condensation of aceto-acetic ester and related substances with urea, thiourea, guanidine, &c. Uracil, C4H402N2, crystallizes in colourless needles, is soluble in hot water and melts with decomposition at 335° C. Hydrouracil, C4H602N2, is obtained by the action of bromine and caustic alkalis on succinamide (H.
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  • Roithner, Monats., 1896, 17, p. 172); by the fusion of 0-aminopropionic acid with urea; by the electrolytic reduction of barbituric acid (J.
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  • Tafel, Ber., 1900, 33, p. 3385), and by the condensation of acrylic acid with urea at 210-220° C. (E.
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  • It dissolves readily in water and the aqueous solution decomposes on standing; a dark-brown flocculent precipitate of azulmic acid, C 4 H 5 N 5 0, separating whilst ammonium oxalate, urea and hydrocyanic acid are found in the solution.
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  • It may also be obtained by oxidizing allylene and propylene with cold potassium permanganate solution, by the hydrolysis of barbituric acid (malonyl urea) with alkalis (A.
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  • Cushny has shown experimentally that slowing of the blood-flow through renal tissue causes less sodium chloride to appear in the urine while the excretion of urea and sulphates remains unaffected; apparently the chloride, being more permeable, is reabsorbed and so only appears to be excreted in less quantity.
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  • It sometimes separates with crystals of a solute as " benzene of crystallization," as for example with triphenylmethane, thio-p-tolyl urea, tropine, &c.
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  • The urea in urine is also rapidly converted by the uro-bacteria into ammonium carbonate.
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  • Other reactions which introduce carboxyl groups into aromatic groups are: the action of carbonyl chloride on aromatic hydrocarbons in the presence of aluminium chloride, acid-chlorides being formed which are readily decomposed by water to give the acid; the action of urea chloride Cl�CO�NH 2, cyanuric acid (CONH) 3, nascent cyanic acid, or carbanile on hydrocarbons in the presence of aluminium chloride, acid-amides being obtained which are readily decomposed to give the acid.
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  • It reacts with alcohol to form chlorcarbonic ester and ultimately diethyl carbonate (see Carbonates), and with ammonia it yields urea.
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  • Formamide, Hconh 2, is obtained by heating ethyl formate with ammonia; by heating ammonium formate with urea to 140° C., 2HCO.
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  • They combine with phenyl isocyanate to form urea derivatives (H.
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  • Ethyl nitrate, C2H5.0N02, is a colourless liquid which boils at 86.3° C. It is prepared by the action of nitric acid on ethyl alcohol (some urea being added to the nitric acid, in order to destroy any nitrous acid that might be produced in secondary reactions and which, if not removed, would cause explosive decomposition of the ethyl nitrate).
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  • When heated with urea to ioo° C. it forms allantoin.
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  • Wdhler oxidized potassium ferrocyanide to potassium cyanate by fusing it with lead or manganese dioxide, converted this cyanate into ammonium cyanate by adding ammonium sulphate, and this on evaporation gives urea, thus: K 4 Fe(NC)r-->K CNO--->NH4CNO->CO (NH2)2 It may also be prepared by the action of ammonia on carbonyl chloride, diethyl carbonate, chlorcarbonic ester or urethane; by heating ammonium carbamate in a sealed tube to 130-140° C.; by oxidizing potassium cyanide in acid solution with potassium permanganate (E.
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  • Urea crystallizes in long needles or prisms which melt at 132° C. and sublime when heated in vacuo.
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  • Bunsen (Ann., 1848, 6 5, p. 8 75) heated urea with an ammoniacal solution of barium chloride to 220° C., and converted the barium carbonate formed into barium sulphate, which is then weighed (see also E.
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  • Knop (ibid., 1870, 9, p. 226), in which the urea is decomposed by an alkaline hypobromite and the evolved nitrogen is measured (see A.
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  • Urea chlorides are formed by the action of carbonyl chloride on ammonium chloride (at 400° C.), or on salts of primary amines.
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  • Substituted urea chlorides are formed by the direct action of chlorine (F.
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  • For example, aa-dimethyl urea is sweet, aß-dimethyl urea is tasteless; p-phenetol carbamide or dulcin, NH 2 CO NH C 6 H 4.0C 2 H 51 is sweet, while the di-p-phenetol carbamide, CO(NH C 6 H 4.0C 2 H 5) 21 is tasteless.
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  • Acetyl urea, NH 2 CO NH 000H 31 formed by the action of acetic anhydride on urea, crystallizes in needles which melt at 212° C. and, on heating, strongly decomposes into acetamide and cyanuric acid.
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  • Methyl acetyl urea, CH 3 NH CO NH000H 31 is formed by the action of potash on a mixture of bromine (I mol.) and acetamide (2 mols.) (A.
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  • Hydrochloric acid at 200° C. decomposes into oxalic acid, carbon dioxide and methylamine, whilst an alcoholic solution of a caustic alkali gives dimethyl urea and oxalic acid.
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  • Barbituric acid (malonyl urea), CH2[C0 NH]C0.2H20, formed by condensing malonic acid with urea (E.
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  • - Nh2c0 Nh C02r]]; by the action of chlorcarbonic esters on urea (H.
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  • Biuret (allophanamide), NH 2 CO NH CO NH 2, is formed by heating urea; by the action of ammonia on allophanic ester; and by heating urea to 140° C. and passing chlorine into the melt at 140-150° C. (J.
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  • When we reflect that some hundreds of thousands of tons of urea are daily deposited, which ordinary plants are unable to assimilate until considerable changes have been undergone, the question is of importance, What happens in the meantime?
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  • For patients with parenchymal liver disease, increasing levels of the International Normalized Ratio (INR) and urea indicated decreasing survival probabilities.
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  • Unlike urea, Clearway products do not degrade to form ammonia, and are therefore not toxic to fish.
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  • Urography Care should be exercised in patients with moderate to severe impairment of renal function (as reflected by a raised blood urea).
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  • The cream is an intense formula containing urea, which is the body 's natural moisturizer.
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  • Breath tests You may also attend our unit for a hydrogen breath test or urea breath test.
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  • In the second part of your question you ask about the symptoms of specific disorders of the urea cycle.
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  • For all the urea inclusion compounds studied, the optimum c g is ca.
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  • Bat urine is composed of 70% urea which decays to form dilute ammonia and other compounds.
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  • In the kidney all the urea in the blood is excreted, along with a varying amount of water.
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  • Urea: This is the tacky, sticky part of the urine.
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  • The urochorome and urea are simple to remove with almost any type of household cleaner.
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  • Urine ammonia, formed from the breakdown of urea by fecal bacteria, is irritating to sensitive infant skin.
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  • Some doctors may recommend preparations containing urea, lactic acid, or alpha-hydroxy acid.
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  • Diagnostic testing will include a complete blood count (CBC), electrolytes (sodium, potassium, chloride) and other blood chemistries, blood urea nitrogen (BUN), and urinalysis.
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  • Whether you have kidney problems or not it is important to know that excess protein makes levels or urea increase, causing the kidneys to work harder.
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  • Protein digestion results in an increase of urea and uric acid in your blood.
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  • By using urea, guanidine, thiourea and related compounds instead of amidines, one obtains the uracils.
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  • This dogma was shaken by Wohler's synthesis of urea in 1828.
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  • But the belief died hard; the synthesis of urea remained isolated for many years; and many explanations were attempted by the vitalists (as, for instance, that urea was halfway between the inorganic and organic kingdoms, or that the carbon, from which it was obtained, retained the essentials of this hypothetical vital force), but only to succumb at a later date to the indubitable fact that the same laws of chemical combination prevail in both the animate and inanimate kingdoms, and that the artificial or laboratory synthesis of any substance, either inorganic or organic, is but a question of time, once its constitution is determined.'.
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  • Salicylic acid and salicin (q.v.) share the properties common to the group of aromatic acids, which, as a group, are antiseptic without being toxic to man - a property practically unique; are unstable in the body; are antipyretic and analgesic; and diminish the excretion of urea by the kidneys.
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  • It was first prepared by C. Scheele and is formed when urea HO C N is treated with water.
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  • The diketotetrahydrotriazoles, or urazoles, are formed by condensing urea derivatives with hydrazine salts, urazole itself resulting by the action of urea or biuret on hydrazine or its salts.
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  • In regard to methods and apparatus, mention should be made of his improvements in the technique of organic analysis, his plan for determining the natural alkaloids and for ascertaining the molecular weights of organic bases b y means of their chloroplatinates, his process for determining the quantity of urea in a solution - the first step towards the introduction of precise chemical methods into practical medicine - and his invention of the simple form of condenser known in every laboratory.
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  • Other reactions which introduce carboxyl groups into aromatic groups are: the action of carbonyl chloride on aromatic hydrocarbons in the presence of aluminium chloride, acid-chlorides being formed which are readily decomposed by water to give the acid; the action of urea chloride Cl�CO�NH 2, cyanuric acid (CONH) 3, nascent cyanic acid, or carbanile on hydrocarbons in the presence of aluminium chloride, acid-amides being obtained which are readily decomposed to give the acid.
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  • ALLOXAN, or Mesoxalyl Urea, C 4 H 2 N 2 0 4 or CO NCO an oxidation product of uric acid, being NNH - CO/ obtained from it by the action of cold nitric acid, C 5 H 4 N 4 03 -}- H 2 O + 0= C4H2N204 -FCO(NH 2) 2.
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  • Zinc and hydrochloric acid in the cold convert it into alloxantin, hydroxylamine gives nitroso-barbituric acid, C 4 H 2 N 2 0 3: NOH, baryta water gives alloxanic acid, C 4 H 4 N 2 0 5, hot dilute nitric acid oxidizes it to parabanic acid, hot potassium hydroxide solution hydrolyses it to urea and mesoxalic acid and zinc and hot hydrochloric acid convert it into dialuric acid, C4H4N204.
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  • Formamide, Hconh 2, is obtained by heating ethyl formate with ammonia; by heating ammonium formate with urea to 140° C., 2HCO.
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  • With urea it gives " /CH NN quinazolone I, and with mandelic nitrile and its H /C0 homologues it forms oxazole derivatives (S.
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  • But it was the achievement of Wailer alone, in 1828, to break down the barrier held to exist between organic and inorganic chemistry by artificially preparing urea, one of those substances which up to that time it had been thought could only be produced through the agency of "vital force."
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  • When heated with urea to ioo° C. it forms allantoin.
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  • UREA, or Carbamide, Co(NH2)2, the amide of carbonic acid, discovered in 1773 by H.
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  • In this reaction urea is heated in a dry tube until it gives off ammonia freely; the residue is dissolved in water, made alkaline with caustic soda, and a drop of copper sulphate solution is added, when a fine violet-red coloration is produced.
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  • Liebig (Ann., 18 53, 8 5, p. 289) precipitates dilute solutions of urea with a dilute standard solution of mercuric nitrate, using alkaline carbonate as indicator.
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  • Riegler (ibid., 18 94, 33, p. 49) decomposes urea solutions by means of mercury dissolved in nitric acid, and measures the evolved gas.
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  • Urea chlorides are formed by the action of carbonyl chloride on ammonium chloride (at 400° C.), or on salts of primary amines.
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  • Urea chloride, NH 2 CO C1 (L.
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  • Nitrourea, H 2 N CO NH NO 2, prepared by adding urea nitrate to wellcooled concentrated sulphuric acid (J.
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