The volume transition induced by the addition of calcium into lightly cross-linked fully neutralized sodium polyacrylate hydrogels, swollen in 40 mM NaCl solutions, is investigated by osmotic swelling pressure and small-angle neutron scattering (SANS) measurements. In this reversible transition, the polymer volume fraction æ changes by more than an order of magnitude. The longitudinal osmotic m...

Micro-osmotic manipulation was used to determine the influence of osmotic contraction on the expansion potential of individual protoplasts isolated from rye (Secale cereale L. cv Puma) leaves. For protoplasts isolated from leaves of nonacclimated plants (NA protoplasts), osmotic contraction in sufficiently hypertonic solutions (>1.53 osmolal) predisposed the protoplasts to lysis during osmotic ...

Dear Sir: In 1964 Savitz, Sidel, and Solomon (1964) produced evidence that the relation of red cell volume to the reciprocal of the external osmotic pressure was linear in a range from 480 to 192 milliosmols. From Savitz, Sidel, and Solomon's results, it may be calculated that the mean fraction of cell water which is apparently osmotically active was 0.81 over the hypertonic ranges of their exp...

Efforts were made to estimate the water potential difference that is required, between rapidly growing oat coleoptile cylinders and dilute medium, to support the rate of water uptake involved in elongation, (a) by the traditional method of determining the concentration of mannitol in which the tissue neither gains nor loses water, and (b) by measuring the rates of osmotic exchanges induced by t...

Electron microscope observations are consistent with the interpretation that the elements of the endoplasmic reticulum are osmotically active in situ as well as after isolation. More recently, it has been reported that microsomal suspensions equilibrate almost completely with added C(14)-sucrose and that no osmotic behavior is evident from photometric data. These findings were considered at var...