Growth oxalic acid

The results of experiments conducted by MacKenzie and McCollum (15) indicate that the effect of dietary oxalic acid on the rat depends on the composition of the diet. There was no effect on rate of growth or calcium excretion of 50 g rats fed for 10 weeks a diet containing 0.6% calcium, 0.7% phosphorus, and optimum vitamin D, when levels of potassium oxalate up to 2.5% were fed. The percent bone ash on the 2.5% oxalate diet was somewhat lower than on the control diet. On a 0.35% calcium, 0.35% phosphorus, and vitamin D-free diet, 1.7% potassium oxalate resulted in restricted growth and bone formation of weanling rats. 

Spiers (18) reported that the feeding of 14% dried New England spinach in the diet resulted in decreased growth and less calcium retention, as determined by body calcium content (Figure 3). Rats 28 days old were fed until 60 days of age. All diets contained about 0.3% calcium, and in the control diet practically all of the calcium was from skim milk. In the other diets, one-half of the skim milk was replaced by turnip greens, tendergreens, collards, kale, or New Zealand spinach to furnish an equal amount of calcium. Spinach was the only one of the greens fed which contained considerable oxalic acid. The calcium of the spinach appeared not only to be utilized poorly, but spinach also impaired utilization of the milk calcium. Food intake of the rats on the spinach diet was also lower. 

Fitzhugh and Nelson (19) found that oxalic acid up to 1.2% of the diet did not affect growth or mortality rate of rats fed oxalic acid for 1 year. Microscopic pathological examination showed no major visceral damage, but some of the rats showed slight periportal hypertrophy of the hepatic cells along with slight centrolobular atrophy. 

In a study by Mueller and Cooney (21) rats fed a diet containing 0.45% calcium and 16% cocoa powder showecf a lower growth rate and body calcium than those on a control diet. However, oxalic acid did not account for the total decrease in body calcium. Rats 25-27 days old were pair-fed the basal ration for 5 weeks. The only variable in the ration was cocoa. The decreased growth rate occurred in the cocoa-fed rats in spite of the fact that they received more calories, protein, calcium and phosphorus than controls. 

Goldman M, Doering GJ, Neilson RG Effect of dietary ingestion of oxalic acid on growth and reproduction in male and female Long-Evans rats. Res Commun Chem Pathol Pharmacol 18 369-372, 1977... 

When a solid gel has been secured, nearly fill each test tube with a solution containing 8 per cent of oxalic acid, to act as a reducing agent. The growth of crystals can be observed within a few hours, and in a few days it will... 

M. Wenger, J. Bernstein, An alternate crystal form of gabapentin a cocrystal with oxalic acid, Cryst. Growth Des. 8 (2008) 1595-1598. 

The growth of porous oxide on aluminum in various electrolytes under anodic bias has been studied for some time [10]. When aluminum is anodized in certain electrolytes, like phosphoric, sulfuric or oxalic acids, using a two-step process followed by etching, an array of close packed cells (pores) arranged in a near hexagonal pattern develops. Each cell contains a cylindrical pore and the axis of the cell is perpendicular to the surface. 

The rotational speeds of the six-bladed stirrers that were used corresponded to power inputs of 0.02 and 0.18 watt/liter at speeds of 125 and 250 rpm, respectively. Concentrations of oxalic acid during precipitation and crystal growth in the stirred tank reactors were varied by changing the flow ratio of oxalic acid-to-waste solution while maintaining the nitric acid concentration constant at 0.9 fl. Permissible nitric acid concentrations for the 0PIX process (4, 6, 7) are 0.5 to about 1.0 M HNO3. Yields of precipitate were determined on the basis of praseodymium recovery. Tracer 142pr (half-life = 19.2 day, 1.6-MeV y-ray) was used to measure yields. 

Figure 6. Thermodynamic efficiency, of aerobic growth with NH, as the nitrogen source, plotted as a function of the degree of reduction, y, of the substrate. Theoretical limits due to the second law and C-limitation. Shown are averages of experimental data for methane (%), n-alkanes ( ), methanol (fH), ethanol C ), glycerol (9), mannitol (O), acetic acid (A), lactic acid glucose ( ), formaldehyde (V), gluconic acid ( ), succinic acid ( ), citric acid ( ), malic acid (9), formic acid ( ), oxalic acid (A)-...

Chemical precipitation is a popular method for synthesizing solid materials from solution in which a liquid-phase reaction is utilized to prepare insoluble compounds. The precipitates are composed of crystalline or amorphous fine particles. Usually, rare earth oxides are prepared by calcinations of the hydroxide or oxalate gel precipitated from a reaction of an aqueous or alcohol solution of inorganic salt (nitrate, chloride, sulfate, and ammonium nitrate, etc.) with an alkali solution (NaOH, NH4OH, and (NH2)2 H20) or an oxalic acid solution [15-21]. However, it is very difficult to obtain ultrafine particles because of growth and sintering of the particles during the calcinations. 

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