Conductance of a single molecule anchored by an isocyanide substituent to gold electrodes

The effect of anchoring group on the electrical conductance of a single molecule bridging two Au electrodes was studied using di-substituted (isocyanide (CN-), thiol (S-) or cyanide (NC-)) benzene. The conductance of a single Au/1,4-diisocyanobenzene/Au junction anchored by isocyanide via a C atom (junction with the Au-CN bond) was $3 \times 10 ^{-3} G_{0}$ ($2e^{2}/h$). The value was comparable to $4 \times 10 ^{-3} G_{0}$ of a single Au/1,4-benzenedithiol/Au junction with the Au-S bond. The Au/1,4-dicyanobenzene/Au molecular junction with the Au-NC bond did not show well-defined conductance values. The metal-molecule bond strength was estimated by the distance over which the molecular junction was stretched before breakdown. The stretched length of the molecular junction with the Au-CN bond was comparable to that of the Au junction, indicating that the Au-CN bond was stronger than the Au-Au bond.Comment: 3 figures, to be appear in Appl. Phys. Let

Performance of alumina-supported Pt catalysts in an electron-beam-sustained CO2 laser amplifier

The performance of an alumina-supported Pt catalyst system used to maintain the gas purity in an electron-beam-sustained (636) isotope CO2 laser amplifier has been tested. The system characteristics using the two-zone, parallel flow reactor were determined for both continuous- and end-of-day reactor operation using on-line mass spectrometric sampling. The laser amplifier was run with an energy loading of typically 110 J-l/atm and an electron-beam current of 4 mA/sq cm. With these conditions and a pulse repetition frequency of 10 Hz for up to 10,000 shots, increases on the order of 100 ppm O2 were observed with the purifier on and 150 ppm with it off. The 1/e time recovery time was found to be approximately 75 minutes

Chromosome 9p deletion in clear cell renal cell carcinoma predicts recurrence and survival following surgery

BACKGROUND: Wider clinical applications of 9p status in clear cell renal cell carcinoma (ccRCC) are limited owing to the lack of validation and consensus for interphase fluorescent in situ hybridisation (I-FISH) scoring technique. The aim of this study was to analytically validate the applicability of I-FISH in assessing 9p deletion in ccRCC and to clinically assess its long-term prognostic impact following surgical excision of ccRCC. METHODS: Tissue microarrays were constructed from 108 renal cell carcinoma (RCC) tumour paraffin blocks. Interphase fluorescent in situ hybridisation analysis was undertaken based on preset criteria by two independent observers to assess interobserver variability. 9p status in ccRCC tumours was determined and correlated to clinicopathological variables, recurrence-free survival and disease-specific survival. RESULTS: There were 80 ccRCCs with valid 9p scoring and a median follow-up of 95 months. Kappa statistic for interobserver variability was 0.71 (good agreement). 9p deletion was detected in 44% of ccRCCs. 9p loss was associated with higher stage, larger tumours, necrosis, microvascular and renal vein invasion, and higher SSIGN (stage, size, grade and necrosis) score. Patients with 9p-deleted ccRCC were at a higher risk of recurrence (P=0.008) and RCC-specific mortality (P=0.001). On multivariate analysis, 9p deletion was an independent predictor of recurrence (hazard ratio 4.323; P=0.021) and RCC-specific mortality (hazard ratio 4.603; P=0.007). The predictive accuracy of SSIGN score improved from 87.7% to 93.1% by integrating 9p status to the model (P=0.001). CONCLUSIONS: Loss of 9p is associated with aggressive ccRCC and worse prognosis in patients following surgery. Our findings independently confirm the findings of previous reports relying on I-FISH to detect 9p (CDKN2A) deletion

SCUBA - A submillimetre camera operating on the James Clerk Maxwell Telescope

The Submillimetre Common-User Bolometer Array (SCUBA) is one of a new generation of cameras designed to operate in the submillimetre waveband. The instrument has a wide wavelength range covering all the atmospheric transmission windows between 300 and 2000 microns. In the heart of the instrument are two arrays of bolometers optimised for the short (350/450 microns) and long (750/850 microns) wavelength ends of the submillimetre spectrum. The two arrays can be used simultaneously, giving a unique dual-wavelength capability, and have a 2.3 arc-minute field of view on the sky. Background-limited performance is achieved by cooling the arrays to below 100 mK. SCUBA has now been in active service for over a year, and has already made substantial breakthroughs in many areas of astronomy. In this paper we present an overview of the performance of SCUBA during the commissioning phase on the James Clerk Maxwell Telescope (JCMT).Comment: 14 pages, 13 figures (1 JPEG), Proc SPIE vol 335

Design study of Low Loss Single-Mode Hollow Core Photonic Crystal Terahertz Waveguide with Support Bridges

We present a design study of an all-polymer low loss single-mode hollow-core photonic crystal (HCPC) terahertz (THz) waveguide with dielectric bridges used as mechanical supports. By exploiting a modal-filtering effect and Brewster phenomenon, we maximize the loss discrimination between the fundamental and other higher order modes resulting in an effectively single-mode operation, though the HCPC THz waveguide is ostensibly multi-mode. Owing to the use of support bridges, which increase the propagation loss, the non-ideal HCPC THz waveguide has higher loss than an ideal one. Nonetheless, the propagation loss of the fundamental HE11 mode can still be minimized, to lower than 5 dB/m over the frequency range from 0.75 to 1.1 THz. In addition, the group velocity dispersion of the HE11 mode is less than -0.5 ps/THz/cm

One Health for a changing world: new perspectives from Africa

The concept of One Health, which aims to drive improvements in human, animal and ecological health through an holistic approach, has been gaining increasing support and attention in recent years. While this concept has much appeal, there are few examples where it has been successfully put into practice. This Special Issue explores the challenges in African contexts, with papers looking at the complex interactions between ecosystems, diseases and poverty dynamics; at underlying social and political dimensions; at the potentials for integrative modelling; and at the changes in policy and practice required to realise a One Health approach. This introductory paper offers an overview of the 11 papers, coming from diverse disciplinary perspectives, that each explore how a One Health approach can work in a world of social, economic and environmental change

'If I had a family, there is no way that I could afford to work here': juggling paid and unpaid care work in social services

Drawing on three case studies in each of Australia, New Zealand and Scotland, this article explores how care workers employed in the social services sector negotiate their unpaid care responsibilities in the context of lean work organization and low pay. For younger workers, the unrelenting demands of service provision and low pay made any long-term commitment to working in social services unrealistic, while many female workers experienced significant stress as they bent their unpaid care responsibilities to the demands of their paid work. However, male workers, less likely to have primary caring responsibilities, appeared less troubled by the prioritizing of paid over unpaid care work and less likely to self-exploit for the job. At the same time, there is a widespread acceptance across different national and organizational contexts that the work/family juggle is a personal responsibility rather than a structural problem caused by the demands of underfunded and overstretched organizations