Correlation between calcium and

Figure 2. Correlation between calcium and sulfate concentration in western precipitation. Data for 1981-1984 - annual averages of NADP stations. (From Hidy Young, Environ. Res. Tech., unpubl. report.)...

Studies of oxygen isotopic fractionation in inorganic precipitates provide conflicting evidence for a correlation between fractionation and precipitation rate. A correlation between the isotopic composition of the inorganic precipitates and the proportion of carbonate in the carbonate-bicarbonate solution (Figure 3.16) was observed by McCrea (1950). He hypothesized that, when first formed, the calcium... 

The substitution pattern of the 4-aromatic residue is also important for the activity, the ortho-substitution being the best one in terms of potency and selectivity. A Hansch analysis on a series of ortho-derivatives has shown a significant correlation between calcium antagonist activity and steric hindrance of the substituent, while no relationship was found for either electronic or lipophilic parameters [3]. The best SAR correlation was obtained when the B1 steric parameter (the Verloop parameter) was introduced into the analysis [4]. The calcium channel-blocking activity increases as B1 increases, which probably indicates that steric hindrance in the ortho-position is required to fix the dihydropyridine structure into a favorable conformation in which the aromatic group is approximately perpendicular to the dihydropyridine ring (Fig. 7.12). 

The ability to overcome MDR in many 1,4-DHPs varies considerably with the nature of the 3,5-substituents. The pyridylalkyl esters are specially suitable, as in the case of NIK-250 (46) [82,83] related derivatives bearing dihydro-1,4-dioxene, dihydro-1,4-dithiane or dihydropyran substituents at C-4 [84]. Other representatives of this group that contain an alkyl group at C-4 (19 (47)) have also shown potent and selective anti-MDR activity [85]. Compounds PAK-200 (48) [86,87] and PAK 104P (49) [88] exemplify the absence of correlation between calcium channel and MDR antagonism, since neither N-alkyl-l,4-DIIPs nor pyridines have significant calcium channel-blocking activity. 

Unlike magnesium, calcium, and strontium, there is no significant trend between dissolved barium and chlorinity or salinity. There is, however, a general inverse correlation between barium and SOq (Figure 7), which is consistent with the hypothesis that equilibrium with respect to barite (BaSOq) may be the factor controlling barium concentrations (Kharaka and Berry, 1974 Hanor, 2001). 

The amounts of strontium found in the flora correlate positively and species-specifi-cally with species-specific amounts of Ca (Table 6.21). Although both elements were apparently taken up in a similar ratio, Ca-rich species or parts of plants were found also to contain high levels of Sr, whereas Ca-poor species proved to be Sr-poor. The almost constant Ca Sr ratio may reduce the occurrence of Sr exposure, and may also be the cause of considerable changes in the proportions of both elements in the skeletons of animals and humans. The cells of plants are unable to distinguish between calcium and strontium (Anke et al. 1999). 

There is a strong correlation between hypercalcemia and hypertension (9,10). Black males may have a higher risk for this side effect (H). Caution must be used when treating hypercalcemia-induced hypertension since thiazide diuretics can transiently produce hypercalcemia. With long-standing hypercalcemia, calcium may be deposited on the cardiac valves and coronary arteries (12.). Another cardiovascular side effect of hypercalcemia is lengthening of the ECG OT interval. 

In order to establish a quantitative correlation between calcium transport and ATP splitting, i.e. the degree of coupling of the transport system, calcium uptake and calcium-dependent ATP splitting must be measured simultaneously. 

Pluta, M., Murariu, M., Ferreira, A.D.S. et al. (2007) Polylactide compositions. 11. Correlation between morphology and main properties of PLA/calcium sulfate composites. Journal of Polymer Science Part B Polymer Physics, 45, 2770-2780. 

M. Body, G. Silly, C. Legein, J.-Y. Buzare, Correlation between environment and isotropic chemical shift in barium and calcium fluoroaluminates, Inorg. Chem., 43, 2474—2485 (2004). 

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