Context. The infrared wide-field camera (WFCAM) is now in operation on the 3.8 m UK Infrared Telescope on Mauna Kea. WFCAM currently has the fastest survey speed of any infrared camera in the world, and combined with generous allocations of telescope time, will produce deep maps of the sky from Z to K band. The data from a set of public surveys, known as UKIDSS, will be initially available to astronomers in ESO member states, and later to the world. Aims. In order to maximise survey speed, the WFCAM field of view was required to be as large as possible while incorporating conventional infrared-instrument design features such as a cold re-imaged pupil stop and cryogenic optics and mechanisms. Methods. The solution adopted was to build a cryogenic Schmidt-type camera, mounted forward of the primary mirror, which illuminates a very large 0.9• diameter focal plane, containing four 2k × 2k HgCdTe Rockwell detectors. Results. Following several commissioning periods during which the camera, focal plane and telescope optical axes were successfully co-aligned, WFCAM now operates close to specifications, regularly achieving 0.7 FWHM images over the full field. Projects which already report excellent results include the detection of variability in young stellar clusters, as well as preliminary deep IR imaging of the Subaru and XMM-Newton deep field.
The external region of a cell membrane, known as the glycocalyx, is dominated by glycosylated molecules, which direct specific interactions such as cell-cell recognition and contribute to the steric repulsion that prevents undesirable non-specific adhesion of other molecules and cells. Mimicking the non-adhesive properties of a glycocalyx provides a potential solution to the clinical problems, such as thrombosis, that are associated with implantable devices owing to non-specific adsorption of plasma proteins. Here we describe a biomimetic surface modification of graphite using oligosaccharide surfactant polymers, which, like a glycocalyx, provides a dense and confluent layer of oligosaccharides. The surfactant polymers consist of a flexible poly(vinyl amine) with dextran and alkanoyl side chains. We show that alkanoyl side chains assemble on graphite through hydrophobic interaction and epitaxial adsorption. This constrains the polymer backbone to lie parallel to the substrate, with solvated dextran side chains protruding into the aqueous phase, creating a glycocalyx-like coating. The resulting biomimetic surface is effective in suppressing protein adsorption from human plasma protein solution.
ObjectivesTo investigate the use of oral anticoagulants (AC) and antiplatelet agents (AP) in the management of atrial fibrillation (AF) among patients in primary care in England.DesignEpidemiological study.Setting1857 general practices in England representing a practice population of 13.1 million registered patients.Patients231 833 patients with a history of AF.Main outcome measuresThe primary outcome was AC and AP use by CHADS2 score and age groups <30 years, 30–49 years, 50–64 years, 65–79 years and >79 years.Results231 833 patients with a history of AF were identified, giving a prevalence among uploading practices of 1.76%. Prevalence of AF varied markedly between practices, related to differing practice age profiles. The total number of patients with AF in a practice was strongly predicted by the number of patients aged 65 years and over in the practice. 57.0% of the AF population had a CHADS2 score ≥2 and 83.7%≥1. 114 212 (49.3%) patients received AC therapy. AC uptake increased with increasing CHADS2 score up to a score of 3, but thereafter reached a plateau. Among 132 099 patients with a CHADS2 score ≥2, 72 211 (54.7%) received an AC, 14 987(11.3%) were recorded as having a contraindication or having declined AC therapy, leaving 44 901 (34.0%) not on AC therapy and without a recorded contraindication or recorded refusal. Among patients not prescribed an AC, 79.9% were prescribed an AP. The use of AC declined in the elderly (for CHADS2≥2, 47.4% of patients ≥80 years, compared with 64.5% for patients aged <80 years, p<0.001). By contrast, AP uptake was more prevalent among elderly patients.ConclusionsOver one-third of patients with AF and known risk factors who are eligible for AC do not receive them. There is a high use of AP among patients not receiving AC. Uptake of AC is particularly poor among patients aged 80 years and over.
We report on submillimetre (submm) observations of three high-redshift quasars (z > 6) made using the SCUBA camera on the James Clerk Maxwell Telescope (JCMT). Only one of the sample was detected (>10σ significance) at 850 µm -SDSS J1148+5251 (z = 6.43). It was also detected at 450 µm (>3σ significance), one of the few quasars at z > 4 for which this has been the case. In combination with existing millimetric data, the 850-and 450-µm detections allow us to place limits on the temperature of the submm-emitting dust. The dust temperature is of no trivial importance given the high redshift of the source, since a cold temperature would signify a large mass of dust to be synthesized in the little time available (as an extreme upper limit in only 0.9 Gyr since z = ∞). We find, however, that the combined millimetre and submm data for the source cannot simply be characterized using the single-temperature greybody fit that has been used at lower redshifts. We discuss the results of the observing and modelling, and speculate as to the origin of the deviations.
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