1,086 research outputs found

    Research and development of HgZnTe as an infrared material

    Get PDF
    Interfacial morphology and Fermi level pinning behavior at the interfaces of Al, Ag, and Pt with UHV-cleaved CdTe and ZnTe have been studied using X-ray and ultraviolet photoemission spectroscopies. Results are compared to metal/HgCdTe interface formation, where the weak HgTe bond and consequent ease of Hg loss strongly influence semiconductor disruption and metal-semiconductor intermising. For Al/CdTe, the strong Al-Te reaction yields a significantly more extensive Al-Te reacted region than has been observed for HgCdTe. The Al/ZnTe interface is observed to be more abrupt than Al/CdTe. The final Fermi level pinning positions, Ef-Evbm for Al, Ag, and Pt on p-type CdTe and p-ZnTe have been determined. Efi is found to be roughly the same for both CdTe and ZnTe, with the value for ZnTe lying approximately 0.2 eV closer to the VBM for all three metals. From these results, one would expect Schottky barriers of about the same height for these metals on p-CdTe and p-ZnTe; and also that, in principle, metal interfaces with the two alloys HgCdTe and HgZnTe would have the same properties. Comparisons and implications for electrical behavior of metal contacts to the alloys are discussed

    A slowly activating voltage-dependent K+ current in rat pituitary nerve terminals.

    Get PDF
    A novel slowly activating voltage-dependent K+ current was observed in isolated nerve terminals from rat neurohypophysis using the whole-cell configuration of the patch-clamp technique. 2. The activation kinetics of the slow current could be fitted assuming Hodgkin--Huxley-type kinetics, an exponential, n, of 1.3 and activation time constants decreasing from 4 s at -50 mV to 0.7s at +40 mV. 3. A positive shift of reversal potential was observed when [K+] was increased in the bath solution. The current is carried mainly but not exclusively by K+ ions. 4. When intracellular free [Mg2+] was low (approximately 60 microM), average current density was 74 pA pF-1 at membrane potentials around 0 mV. In 83% of nerve terminals current amplitude was > 10 pA pF-1. 5. The slow current was never observed when the pipette contained 4.6 mM free Mg2+. At a physiological level of free Mg2+ (0.5 mM) the average current density was 16 pA pF-1. 6. When nerve terminals were analysed after patch-clamp experiments for vasopressin content by immunodetection, no difference in current amplitude was found between the terminals containing vasopressin and all analysed terminals. 7. The voltage dependence of activation was fitted by a Boltzmann equation giving a half-activation potential of -37 mV and a slope factor of about 9 mV. 8. Tail current deactivation kinetics was biexponential with time constants of 0.12 and 1.5s. Kinetics was dependent on the duration of the activating pulse. 9. Noise analysis of the slow current indicated a single-channel current of 0.33 pA at +6 mV, corresponding to a single-channel conductance of 4.3 pS. 10. This is the first demonstration of a current similar to the slow K+ current, IKs, in a neurone, suggesting that a protein similar to the IKs-inducing channel protein IsK (minK) may be present in peptidergic nerve terminals. 11. The activation properties are consistent with a role of the slow current in inhibition of excitability, at least at the level of the nerve terminal

    The management of distal ulnar fractures in adults: a review of the literature and recommendations for treatment

    Get PDF
    The distal ulna represents the fixed point around which the radius and the hand acts in daily living. The significance of distal ulnar fractures is often not appreciated and often results in inadequate treatment in comparison to its larger counterpart; the radius. There is little guidance in the current literature as how to manage these fractures and their associated injuries. This paper aims to critically review the current literature and combine it with treatment suggestions based on the experience of the authors to help guide investigation and management of these often complex injuries

    The effect of brief digital interventions on attitudes to intellectual disability: Results from a pilot study

    Get PDF
    BACKGROUND: Evidence on the effects of contact and education based interventions on attitudes is limited in the intellectual disability field. This study compared the effects of brief interventions with different education, indirect and imagined contact components on lay people's attitudes. MATERIALS AND METHODS: 401 adult participants were randomised to six digital brief interventions consisting of different combinations of education, indirect and imagined contact. Their attitudes, intergroup anxiety and social distance were assessed post-intervention and at four to six-week follow-up. RESULTS: An intervention combining film-based education about intellectual disability and indirect contact had small positive effects on all three outcomes. Social distance was further reduced with the addition of a positively toned imagined contact task. These effects were maintained at follow-up. CONCLUSIONS: A brief film-based digital intervention can have small positive effects on attitudes to people with intellectual disabilities. These may be enhanced by adding positive imagined contact
    corecore