Osmotic concentration

While the osmotic concentration of renal cortical tissue is isotonic, interstitial solute concentration begins to rise at the border between renal cortex and renal medulla to... 

Osmotic concentration kinetics were also studied for the purpose of manufacturing carrot preserves (Singh et al., 1999). The preserve quality was assessed as a function of sugar solution concentration and sample-to-syrup ratio, and the kinetics of preserve manufacture were described using an empirical equation. 

Islam, M.N. and Flink, J.N. 1982. Dehydration of potato. II. Osmotic concentration and its effect on air drying behavior. J. Food Technol. 17, 387-403. 

Volumes of the intracellular and extracellular body fluid compartments are kept constant by the osmotic pressure, which is created by the concentration of dissolved ions (electrolytes) in each compartment. The normal osmotic concentration is in the range of 280-310 mOsm/L. 

X and 4X the normal amount. The osmotic concentration was maintained constant by balancing the NaCI concentration. 

To determine the allelopathic potential of campestris and oleracea var. italica, leachates from each species were made. Extracts were prepared by soaking, for two hr, weighed amounts of fresh or dried material in sufficient doubly distilled water to prepare a 10% extract (of fresh material) or 1.5% extract (of dry material). Extracts were vacuum filtered through paper (Whatman 1). The osmotic concentration was measured with a freezing-point osmometer (0 to 500 mosm) and indicator seeds were soaked in 10 mL of the extract for an hour prior to planting. 

An important functional characteristic of the proximal tubule is that fluid reabsorption is isosmotic that is, proximal reabsorbed tubular fluid has the same osmotic concentration as plasma. Solute and water are transported in the same proportions as in the plasma because of the high water permeability of the proximal tubule. Thus, the total solute concentration of the fluid in the proximal convoluted tubule does not change as the fluid moves toward the descending loop of Henle. The corollary of this high water permeability is that unabsorbable or poorly permeable solutes in the luminal fluid retard fluid absorption by proximal tubules. This is an important consideration for understanding the actions of osmotic diuretics. 

Apart from the utilization of the common mono- and di-saccharides as metabolic substrates for growth and energy, there is little information on the growth effects of externally applied carbohydrates. Some, like D-mannose, D-galactose, and 2-deoxy-D-araWno-hexose, are inhibitory to root growth,718 possibly because they provide a high osmotic concentration in solution, from which they are only indifferently utilized, without being actively phytotoxic. 

The Role of Abscisic Acid as a Stress Hormone. The role of ABA in water stress has been studied most extensively, although there is also evidence for involvement of ABA in other stresses such as salinity, mineral deficiency, high osmotic concentration, and water-logging. A review on the role of ABA in stress phenomena has appeared recently (18). 

When describing how the osmotic concentrations of organisms compare to the osmolality of the surrounding solution, the following terms are employed (for reviews, see Kirschner,... 

In accord with this interpretation, it was observed that high concentrations of sucrose, KC1, and other ionic and nonionic substances restored the accumulation capacity of LB6 cells to normal levels (Table n). The completely osmotic nature of this effect is supported by the findings summarized in Figure 5, which shows that except at very high levels sucrose and KC1 have precisely equal stimulatory effects on glutamate accumulation over a wide range of iso-osmotic concentrations. In contrast to the tenacious retention of accumulated amino acids by nutritionally normal cells, LB6 cells, which have accu-... 

Except for respiratory and dermal insensible water-vapor losses, all remaining water lost by the body contains electrolytes, mainly sodium and chloride. The normal cation and anion constituent composition of the fluid spaces is given in Table IV. In the extracellular fluid space, sodium is the major cation and chloride the major anion. Those two ions constitute 95 of the extracellular fluid osmolality. Changes in plasma sodium concentration reflect changes in extracellular fluid volume. Potassium is the major cellular cation and phosphates and proteins comprise the major anions. The total cellular osmolality (175 + 135 = 310 mosraol/kg H2O) is equal to the total extracellular osmolality (155 + 155 = 310 mosmol/kg HaO) therefore, equal total osmotic concentrations are maintained between two fluid compartments of widely different ionic contents (Table IV). 

The urinary osmolality of normal individuals may vary widely, depending on the state of hydration. After excessive intake of fluids, for example, the osmotic concentration may fall as low as 50 mOsm/kg/H20, whereas in individuals with severely restricted fluid intake, concentrations of up to 1400mOsm/kg/H2O can be observed. In individuals on an average fluid intake, values of 300 to 900 mOsm/kg/H20 are typically seen. If a random urine specimen of a patient has an osmolality of >600 mOsm/kg/H20 (or >850mOsm/kg/ H2O after 12 hours of fluid restriction), it can generally be assumed that the renal concentrating ability is normal. 

El. Eaton, J. W., Koplin, C. F., Swofford, H. S., Kjellstrand, C. M., and Jocob, H. S., Chlorinated urban water A cause of dialysis-induced hemolytic anemia. Science 118, 463-464 (1973). E2. Ehrlich, K., Holland, F., Tumham, T., et al., Osmotic concentration of polypeptides from hemofiltrate of uremic patients. Clin. Nephrol. 14, 31-35 (1980). 

Interestingly, the osmotic concentration of the hemolymph of edematose larvae was nearly normal (28). Apparently sexta larvae have no satisfactory alternative means to eliminate the accumulated ornithine and edema results either from an active attempt to maintain osmotic homeostasis in the hemolymph or as the result of passive water retention. 

Garrote, R. L. and Bertone, R. A. 1989. Osmotic concentration at low temperature of frozen strawberry halves. Effect of glycerol, glucose, and sucrose solution on exudate loss during thawing. Food Science and Technology 22 264-267. 

Osmotic concentration or osmolarity is the term used to describe the osmotic strength of a solution. It depends only on the ratio of the number of solute particles to the number of solvent particles. Thus the chemical nature and size of the solute are not important, only the concentration, expressed in molarity. For instance, a 2 M solution of glucose (a sugar of molecular weight 180) has the same osmolarity as a 2 M solution of albumin (a protein of molecular weight 60,000). 

Osmotic concentration can be considered a simultaneous water and solute diffusion process. As explained by Lerici et al (1988) the membrane is only... 

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