Publications

Surface activity and formation of liq. crystals by didecyldimethylammonium bromide (I) in presence of EtOH was studied. The crit. micelle concn. and the area per mol. increased at EtOH concn. >2 M, in which a significant change in solvent properties occurs. I formed lamellar liq. crystals which were destroyed by the added EtOH, at concn. similar to that which prevented the formation of micelles. [on SciFinder(R)]

Vibrational energies and eigenfunctions of Ar3, including some pertaining to highly excited states, are computed, and insights into their dynamical and structural properties are obtained. The method used employs the vibrational self-consistent-field (SCF) theory in hyperspherical coordinates as a first approximation. Exact results are obtained by configuration interaction, using the SCF states as an efficient basis. A focal point of the study is the effect of three-body potentials on the vibrational spectrum. Axilrod-Teller and other three-body potentials are used to examine this. It is found that the effect of three-body forces on the spectrum is substantial, and larger than effects due to uncertainties in the presently known two-body Ar-Ar potentials. This suggests that experimental spectroscopy of Ar3 may be used to determine reliable three-body forces among Ar atoms. It is also shown that the three-body double-dipole-quadrupole interaction, while less important than the Axilrod-Teller one, has a significant effect on the vibrational spectrum. Finally, a detailed analysis is made of the Ar-Ar distance distributions in the various states, of the structural distributions of Ar3, and of the properties of the wave functions. We find that the wave functions show well-ordered nodal patterns even for the highly excited large-amplitude states. Thus, these states do not correspond qualitatively to ``liquid-like'' behavior of the cluster.

Osteoporosis and fractures are rare in acromegaly. An 84-year-old acromegalic woman sustained a fractured neck of femur in a fall. Histomorphometric analysis of an iliac crest biopsy showed marked osteoporosis and augmented resorption parameters. Cortical plates were very thin and bone volume was 8.5%; 12.5% is the reference value for women at this age. The total resorption surfaces were 23.7% compared with the reference value of 8%. We conjecture that postmenopausal and involutional osteoporosis were far advanced before the development of acromegaly, explaining the coexistence of the two conditions. Parathormone (65 pmol/l) and 24,25-dihydroxyvitamin D (1.34 ng/ml) levels were within normal limits, but those of 25-hydroxyvitamin D (5.6 ng/ml) and 1,25-dihydroxyvitamin D (15 pg/ml) were markedly decreased.

Ovalbumin was modified to various degrees by acylation of lysine ε-amino groups with stearyl residues. Adsorption isotherms of the modified ovalbumin on hydrophobic silica were obtained. Increase in degree of modification resulted in increased amts. of adsorbed protein. At high modification degree (>40%), practically identical isotherms were obtained. The adsorption data were analyzed by using the Langmuir equation, and it appeared that increase in modification led to decrease in area per adsorbed protein mol., while the adsorption const. remained unchanged. [on SciFinder(R)]

Reviews the book "From Christianity to Judaism: The Story of Isaac Orobio de Castro," by Yosef Kaplan and translated by Raphael Loewe.

The use of solid chitin particles for stabilization of oil-in-water emulsions was evaluated, and it was shown that the chitin particles could adsorb at the oil-water interface. Stable emulsions of paraffin oil in water were obtained at high concns. of chitin particles (2.5% wt./wt.) when the water phase contained no surfactants. In the presence of only 0.0055% wt./wt. Tween 80, stable emulsions were obtained at 0.5% wt./wt. chitin. From zeta potential measurements, it was concluded that the stabilization of the above emulsion did not result from changes in the elec. properties of emulsion droplets. [on SciFinder(R)]