Phosphorus Ratio

The findings of Cox and Imboden (40, 41) were confirmed by Bodansky and Duff (43) who found that the normal calcification of the fetal skeleton depends not only upon the maternal mineral intake but also upon normal function of the parathyroid glands of the mother. 

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Single Haversian systems differ significantly in calcium-phosphorus ratio. 

Bromine/phosphorus synergy was investigated in a 2/1 polycarbonate/ polyethylene terephthalate blend. Synergy was demonstrated when blends of brominated and phosphorus compounds were used. The synergy is even more pronounced with a compound containing both elements in the same compound. This was dependant on the bromine/phosphorus ratio in the compound. Phosphorus was shown to be 9 to 10 times more effective than bromine in this resin blend. 

Dietary phosphorus also affects calcium metabolism. Polyphosphate decreases calcium absorption in young men while orthophosphate supplement does not (26J. However, in the rat all forms of phosphate decrease calcium absorption about equally (31). However, widely divergent dietary calcium phosphorus ratios do not seem to affect calcium utilization by people as long as there is adequate phosphorus intake (32). In general phosphorus stimulates calcium retention in man (3277... 

The metal to phosphorus (or arsenic) ratio varies between 1 1 (alkali metal phosphanides and arsanides) and 2 1 for bis(alkali metal) phosphanediides or arsanediides. In general, these compounds form pnictogen polyhedra with the faces being capped by monovalent metal atoms. For the alkaline-earth metal phosphorus cages, metal to phosphorus ratios between 1 2 for alkaline earth metal bis(phosphanides) and 1 1 for the phosphanediides of the divalent cations are possible. 

Milk is one of the best dietary sources of calcium, not only because of the significant quantity of the mineral present but also because of (1) its calcium-to-phosphorus ratio (1.3 1), which is conducive to optimal skeletal growth, and (2) the presence of nutrients such as lactose and vitamin D in vitamin D-fortified milk, which promote calcium absorption (Ziegler and Fomon 1983 Schaafsma 1983 Renner 1983). 

The teichoic acid which had not been subjected to ion-exchange chromatography contained D-alanine in characteristic, labile, ester linkage. It contained insufficient glucose to accommodate all of the alanine ester residues (alanine phosphorus ratio, 0.89 1), and the kinetics of the reaction with hydroxylamine indicated that all of the alanine is attached to the available hydroxyl groups at C-2 of glycerol residues. 

There arc several unique features exhibited by the D vitamins. First, they are not required nutritionally al all if the organism has access to ultraviolet light (which is present in sunlight). Some animals, kept away from ultraviolet light, require so little D vitamins that the need cannot be demonstrated using ordinary diets. Rats, for example, exhibit a need for D vitamins when the calcium/phosphorus ratio in the diet is about 5 1 but not when it is the more usual 1 1. Chickens, on the other hand, exhibit a need even when the calcium/phosphorus ratio is normal (1.5 1). 

Bone mainly consists of HA, but during the various development stages of bone other calcium phosphates are also found. They occur in the following series, the chemical formula of the calcium -phosphorus ratio Ca/P of which varies from 1.00 to 1.67 not all values between the extremeties are mentioned ... 

Adsorption. Sulfur and phosphorus ratios change with rubbing time. Tribofilms accumulated on the surface become thicker with time. All co-additives cause reduction in ZDDP surface coverage under all conditions studied. A surface force apparatus (SFA), and atomic force microscopy were used to determine tribofilm thiclaiess, molecular structure and mechanical properties. For the neutral ZDDP, monomolecular layer thickness is 1 nm and for basic ZDDP it is 1.6 nm (Sutherland et al., 1993 Bames et al., 2001 Bee et al., 1999 Dacre and Bovington, 1983 Georges et al., 1998 Paddy et al., 1990 Wu and Dacre, 1997). 

Physical parameters By using Table 4.3. The effect of physical parameters such as adsorption, rubbing, temperature, concentration, load, surface roughness on antiwear performance of ZDDPs , which term is described by the physical parameter (a) the tribofilm accumulated on the surface becomes thicker with adsorption time (b) long-chain phosphates are formed on the topmost surface, but short-chain phosphates were present in the bulk (c) sulfur and phosphorus ratio changes with rubbing time and (d) when load increased the concentration of (S) and decreased that of (P) ... 

In the aluminophosphate family, three main structural classes with different metal to phosphorus ratios are known. The layered aluminophosphates normally have P/Al ratios of 4 3 and 3 2 and a new series with P/Al ratio of 2 1 has been reported [25]. The templates play an important role in the formation of these materials and there have been some attempts to rationalize the formation of these solids [25]. The two-dimensional architecture is generally formed by strictly alternating P04 and A104 tetrahedra. Of the four oxygen atoms coordinated to each tetrahedral phosphate, three are shared with adjacent A1 atoms,... 

Mechanical activation apphed to the mentioned reaction was found to be very efficient [45]. For example, molybdenum oxide mechanically activated for several seconds is readily dissolved in hot solution of phosphoric acid to give heteropolyacid. By varying the interaction conditions, one succeeds in obtaining heteropolyacids with different molybdenum to phosphorus ratios. H3PM012O40 can be synthesized in the individual pure state, and HgP2Mo,gOj2 with the purity of 94-98 %. Mo - P mixtures, which are most easily prepared, can be used as acid catalysts without separating into components. Besides the simplicity of preparation. 

A dinuclear compound, (Me2N)3P=N-P(=NH)(NMe2)2, with a high nitrogen phosphorus ratio is the first member of a series of strongly basic, branched polyamino-imino phosphazenes (Scheme 43). ... 

TABLE 15.1 Nitrogen and Phosphorus Ratios, Maryland Coastal Area Organic N, NH3-N, NOj-N, NO3-N, Total N, Total P, ... 

Alterations in systemic calcium-to-phosphorus ratios are another known cause of band keratopathy. This includes hypercalcemia caused by conditions such as hyperparathyroidism, sarcoidosis, and vitamin D intoxication, as well as the elevated serum phosphorus commonly foimd with kidney feilure. Gout can also cause band keratopathy. 

Smith, V. H. (1983). Low nitrogen to phosphorus ratios favor dominance by blue-green algae in lake phytoplankton. Science 221, 669-671. 

Cullen J. T., Chase Z., Coale K. H., Fitzwater S. E., and Sherrell R. M. (2003) Effect of iron limitation on the cadmium to phosphorus ratio on natural phytoplankton assemblages from the Southern Ocean. Limnol. Oceanogr. 48, 1079-1087. 

Anderson L. D., Delaney M. L., and Eaul K. L. (2001) Carbon to phosphorus ratios in sediments implications for nutrient cycling. Global Biogeochem. Cycles 15, 65-80. 

A special relationship betv een calcium and phosphate is suggested by the fact that the calcium/phosphorus ratio in bone is about 2.2/1.0, by weight. As almost all of the body s calcium and most of the body s phosphate occurs in bone, one might expect that the ratio of calcium/phosphorus in the diet that supports maximal growth would be similar to the ratio of these elements in bone. This ratio would be expected to be influenced by the fact that dietary F is more readily absorbed than Ca and by the use of P for soft tissues,... 

The dietary calcium/phosphorus ratio is important for the maintenance of kidney health. Where there is too much phosphate, mineral deposits may develop in the kidneys, in a process called nephiocalcinasis. Female rats are especially prone to nephiocalcinosis, which occurs when the calcium/phosphorus ratio is under 1/0.. For this reason, a recommended Ca/P ratio is 1.66 (the same as 1/0.6) Reeves, 1997). 

Hypocalcemia commonly occurs during the first I or 2 days of life in premature, low-birth-weight infants. The exact mccKaiusm is not clear. Hypocalcemia can also present in newborns fed cow milk, because cow milk contains calcium and phosphorus in a ratio of about 1.34/1.0, by weight. Mother s milk contains relatively less phosphate the calcium/phosphorus ratio is 2.25/1,0. The excess phosphate in cow milk promotes hyperphosphatemia in the newborn. It is thought that plasma phosphate, in elevated concentrations, fonns a complex with plasma calcium. Formation of this complex reduces the levels of free calcium, resulting in symptoms of hypocalcemia. The newborn is not as able to make hormonal adjustments to maintain plasma calcium levels as is the older infant (Mizrachi et al., 1968). 

There is increased sensitivity to vitamin D in patients who are undergoing renal dialysis and who have an abnormal calcium/phosphorus ratio. Patients on continuous ambulatory peritoneal dialysis (CAPD) who develop secondary hyperparathyroidism may already have low bone turnover or adynamic bone lesions, and if treated indiscriminately with calcitriol their low bone turnover can get worse (62). 

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