Gas chromatographic determination of estrone,estradiol and estriol in non-pregnancy plasma

Summary A gas Chromatographic method for the determination of estrone, estradiol and estriol in plasma of normal females is described. Purification is done by means of TLC of the free compounds and the acetates and quantitation is achieved by electron capture-gas chromatography of the estrogen heptafluorobutyrates. Experiments on the validation of the method are described along with some examples of its application.

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Zusammenfassung Eine gaschromatographische Methode zur Bestimmung von Östron, Östradiol und Östriol im normalen weiblichen Plasma wurde beschrieben. Die Reinigung erfolgte durch Dünnschichtchromatographie der freien Verbindungen und ihrer Acetate. Die quantitative Bestimmung wurde gaschromatographisch mit Hilfe eines Elektroneneinfangdetektors an Hand der Östrogenheptafluorobutyrate bewerkstelligt. Versuche zur Bewertung dieser Methode sowie Beispiele für ihre Anwendung wurden beschrieben.

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Supported by USPHS Grants AM 09908 and RCDA 5 K 3-AM-31, 321 (S. K.) and a grant from the Ford Foundation.     

Water-soluble calix[4]resorcarenes as enantioselective NMR shift reagents for aromatic compounds

A tetra L-prolinylmethyl derivative of a tetra-sulfonated calix[4]resorcarene (1) is an effective chiral NMR solvating agent for water-soluble compounds with phenyl, pyridyl, bicyclic aromatic, or indole rings. These aromatic compounds form host-guest complexes with the calix[4]resorcarene in water. Complexation of substrates with the calix[4]resorcarene is likely promoted by hydrophobic effects, and bicyclic substrates have association constants with the calix[4]resorcarene larger than those of similar phenyl-containing compounds. Aromatic resonances of the substrates show substantial upfield shifts because of shielding from the aromatic rings of the calix[4]resorcarene, and several resonances in the 1H NMR spectra typically exhibit enantiomeric discrimination. The extent of enantiomeric discrimination depends in part on interactions of the substituent groups of the substrates with the prolinylmethyl groups of the calix[4]resorcarene. The effectiveness of a calix[4]resorcarene prepared from N-methyl-L-alanine (2) as a chiral NMR discriminating agent is compared to the L-prolinylmethyl derivative.     

The New Test Method for High Velocity Water Jet Impact

Paper presents a simple method of generating a high-speed short water jet (droplet) by over-compression of the water layer sandwiched between bars with high acoustic impedance. The proposed method allows the creation of short high-speed water jets (droplets) with extremely simple and inexpensive equipment. Theoretically, jets with speeds higher than 1500?m/sec can be generated by this method.     

Metal oxidation—II. Kinetics in the thin and very thin film regions under conditions of electron equilibrium

Using the results of Part I, the kinetics of growth of uniform, compact, oxide films, in the thickness range where diffusion in the bulk of the film may be neglected compared with migration, is examined for systems in which electron equilibrium is essentially maintained during film growth. (For such systems, a significant contribution to the space charge in the film is expected only from the mobile defects, cf. Part I). A variety of rate laws are shown to arise as limiting cases, including linear, parabolic, cubic and logarithmic type rate laws. Space charge effects, while relatively unimportant for systems in which ion transport occurs via cation vacancies, can be quite significant for those involving transport via interstitial cations.     

Self-induced shapiro effect in semiconductor superlattices

We observe that the oscillatory motion of photoinjected electron-hole pairs in a biased semiconductor superlattice (Bloch oscillation) is accompanied by a coherent quasi-dc current that is generated by the interaction of the carriers with the self-induced oscillating field. It is shown that this novel macroscopic quantum effect, which is a coherent analog of the Shapiro effect observed in Josephson junctions, can be controlled by changing the spectral position of the exciting laser pulse, which in turn determines the amplitude and phase of the wave packet oscillations. It is thereby possible to coherently drive the electrons either downwards or upwards in the potential of the static field.     

Operator algebras and a theorem of Dieudonne

LetA be aC*-algebra with second dualA″. Let (φ _n)(n=1,...) be a sequence in the dual ofA such that limφ _n(a) exists for eacha εA. In general, this does not imply that limφ _n(x) exists for eachx εA″. But if limφ _n(p) exists whenever p is the range projection of a positive self-adjoint element of the unit ball ofA, then it is shown that limφ _n(x) does exist for eachx inA″. This is a non-commutative generalisation of a celebrated theorem of Dieudonné. A new proof of Dieudonné’s theorem, for positive measures, is given here. The proof of the main result makes use of Dieudonné’s original theorem.