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Photoluminescence from individual InAs/InP quantum dots embedded within a planar n–i structure is studied as a function of vertical electric field. We demonstrate control of the electron number and determine the Stark shift and built-in dipole at zero electric field. In contrast to the well studied InAs/GaAs quantum dot material system, we obtain a built-in dipole which indicates that the electron lies above the hole at zero electric field. The magnitude and direction of the measured dipole suggests a uniform quantum dot composition. The gating principles we demonstrate can be applied to pre-positioned InAs/InP quantum dots, such that arrays of initialized single spins can be employed for quantum information applications. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

We examine the optical mode structure of two-dimensional, photonic crystal microcavities based on triple missing hole defects in hexagonal symmetry, etched air-hole, suspended InP membranes. Polarisation dependent photoluminescence from InAs/InP quantum dots embedded within the cavities is used to explore mode energies and quality factors, Q, as a function of cavity design parameters. Optimised Q values are in excess of 7,500 for the modified y-dipole mode. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Pharmacokinetics and bioavailability of famotidine, a new H2-receptor antagonist, were investigated in healthy subjects in five clinical studies. Linear pharmacokinetics were observed following either intravenous or oral administration. Plasma clearance averaged 463 ml min-1. Renal clearance averaged 310 ml min-1, which exceeded the glomerular filtration rate. Renal excretion was the major route of elimination. Urinary recovery of unchanged drug following intravenous administration was about 67 per cent. Famotidine plasma half-life was approximately 2.6 h. Oral absorption was incomplete. The bioavailability averaged 43 per cent of the dose.

The structure of the tetrameric dianion formed by α-methylstyrene in tetrahydrofuran by reaction with sodium has been examined. Mass spectral, NMR, infrared, and kinetic data all indicate that the structure is rather than the structure which had previously been assumed for this species.