Characterizing the optical response of ultra-low-noise far-infrared 60-110 μm transition edge sensors.

Far-infrared Transition Edge Sensors (TESs) are being developed for the SAFARI grating spectrometer on the cooled-aperture space telescope SPICA. In support of this work, we have devised a cryogenic (90 mK) test facility for carrying out precision optical measurements on ultra-low-noise TESs. Although our facility is suitable for the whole of the SAFARI wavelength range, 34 µm-230 µm, we focus on a representative set of measurements at 60 µm-110 µm using a device having a noise equivalent power of 0.

Evidence of a nonequilibrium distribution of quasiparticles in the microwave response of a superconducting aluminum resonator.

In a superconductor, absorption of photons with an energy below the superconducting gap leads to redistribution of quasiparticles over energy and thus induces a strong nonequilibrium quasiparticle energy distribution. We have measured the electrodynamic response, quality factor, and resonant frequency of a superconducting aluminium microwave resonator as a function of microwave power and temperature. Below 200 mK, both the quality factor and resonant frequency decrease with increasing microwave power, consistent with the creation of excess quasiparticles due to microwave absorption.

Second-trimester Down's syndrome serum screening: double, triple or quadruple marker testing?

Background: The recommendations of the UK National Screening Committee (NSC) are based on the findings of the Serum, Urine and Ultrasound Screening Study (SURUSS). Our study sought to establish if the SURUSS findings, in terms of detection rates (DR) and false-positive rates (FPR) for various second-trimester marker combinations, could be replicated in a local setting.

Methods: We investigated the effects of adding inhibin-A and unconjugated oestriol to our existing double test protocol.

Subclinical hypothyroidism: a comparison of strategies to achieve adherence to treatment guidelines.

Background: Subclinical hypothyroidism is an entity based on the laboratory findings of a raised serum thyrotrophin (TSH) concentration and a normal free thyroxine (FT(4)) concentration. Patients with subclinical hypothyroidism who also have anti-thyroid peroxidase (TPO) antibodies have a higher conversion to overt hypothyroidism than those without, and treatment with thyroxine is recommended.

Method: We audited anti-TPO assay requests within two NHS Trust hospitals, against consensus standards, to ascertain whether a cascade approach to anti-TPO testing and direct advice leads to more appropriate prescribing of thyroxine in general practice.

Mechanisms of activation of phosphoenolpyruvate carboxykinase from Escherichia coli by Ca2+ and of desensitization by trypsin.

The 1.8-A resolution structure of the ATP-Mg(2+)-Ca(2+)-pyruvate quinary complex of Escherichia coli phosphoenolpyruvate carboxykinase (PCK) is isomorphous to the published complex ATP-Mg(2+)-Mn(2+)-pyruvate-PCK, except for the Ca(2+) and Mn(2+) binding sites. Ca(2+) was formerly implicated as a possible allosteric regulator of PCK, binding at the active site and at a surface activating site (Glu508 and Glu511).

Second trimester screening for Down's syndrome: 7 years experience.

Objectives: To evaluate the effectiveness of the first 7 years of a programme for second trimester antenatal screening for Down's syndrome, using alpha-fetoprotein (alphaFP) and total human chorionic gonadotropin (hCG) as maternal serum markers.

Methods: A clinical biochemistry laboratory providing a screening service for four obstetric units. Women attending for antenatal care who accepted an offer of serum screening for Down's syndrome were tested between 15 and 20 weeks gestation.

Accreditation of external quality assessment schemes in the United Kingdom.

There are some 130 pathology external quality assessment schemes available in the United Kingdom. Most are provided from within the National Health Service, but a few from the private sector. At the invitation of the Department of Health, Clinical Pathology Accreditation (UK) Ltd.

New roles and relationships in the NHS--barriers to change.

The incoming Labour Government's vision for reforming the NHS in Scotland was outlined in the White Paper Designed to Care. While bearing similarities to the proposals outlined for the rest of the UK, it also had distinctive differences. Organisational structures, roles, and relationships between the different parts of the NHS were to be fundamentally altered, particularly in primary and community care.

Methyl methacrylate levels in unwashed salvage blood following unilateral total knee arthroplasty.

To evaluate the safety of autologous reinfusion of drain blood in total knee arthroplasty (TKA), eight patients were prospectively evaluated to quantify levels of methyl methacrylate (MMA) monomer in systemic blood, and in their drain blood after unilateral cemented TKA. The systemic blood was analyzed before and after reinfusion of the drain blood. The drain blood was analyzed before reinfusion, and both before and after filtration through a 40-microm filter.

Down's syndrome screening using free beta hCG: instability can significantly increase the Down's risk estimate.

The stability of free beta hCG (human chorionic gonadotrophin) was assessed using a dual alpha-fetoprotein and free beta hCG assay. A significant increase in free beta hCG concentration was observed in heparinized samples left unseparated for 24 h or more, the mean increase in 21 samples being 10.2% after 24 h (P = < 0.

Screening for Down's syndrome: the first two years experience in Bristol.

Objectives: To evaluate the effectiveness of a programme for antenatal screening for Down's syndrome using alpha fetoprotein and total human chorionic gonadotrophin as maternal serum markers.

Setting: A district general hospital providing a screening service to a local purchasing authority and (under contract) to another purchasing authority in the same region.

Methods: Patients were counselled and screened between 15 and 20 weeks gestation and Down's risk estimates calculated using the maternal serum marker results as modifiers of the age related risk.

U.K. multicentre study on blood donors for surrogate markers of non-A non-B hepatitis. Part I: Alanine transferase and anti-HBc testing.

Blood samples from 9,215 blood donors in three U.K. centres (North London, Bristol and Manchester) were tested for their alanine aminotransferase (ALT) level and the presence of anti-HBc and anti-HCV.

Serum alanine transaminase (ALT) reference ranges estimated from blood donors.

It has been suggested that an increase in serum alanine transaminase (ALT) activity in blood donors may identify infection with non-A, non-B hepatitis. To facilitate identification of such donors, the reference range for ALT was measured on a Technicon SMAC 1 Analyser, using serum from 364 blood donors and 567 plasmapheresis donors. The distribution of ALT activities displayed a positive skewness, and so both logarithmic transformation and subsequent calculation of mean and standard deviation as well as non-parametric analysis were used to obtain best estimates of reference ranges for men and women, 5-65 IU/1 and 5-35 IU/1, respectively.