Large angle magnetization dynamics measured by time-resolved ferromagnetic resonance

A time-resolved ferromagnetic resonance technique was used to investigate the magnetization dynamics of a 10 nm thin Permalloy film. The experiment consisted of a sequence of magnetic field pulses at a repetition rate equal to the magnetic systems resonance frequency. We compared data obtained by this technique with conventional pulsed inductive microwave magnetometry. The results for damping and frequency response obtained by these two different methods coincide in the limit of a small angle excitation. However, when applying large amplitude field pulses, the magnetization had a non-linear response. We speculate that one possible cause of the nonlinearity is related to self-amplification of incoherence, known as the Suhl instabilities.Comment: 23 pages, 8 figures, submitted to PR

Eddy-Current Probe Design

This paper describes theoretical and experimental work directed toward finding the optimum probe dimensions and operating frequency for eddy current detection of half-penny surface cracks in nonmagnetic conducting materials. The study applies to probes which excite an approximately uniform spatial field over the length of the crack at the surface of the material. In practical terms, this means that the probe is not smaller than the crack length in any of its critical dimensions

Comparison of two self-reported measures of physical work demands in hospital personnel: A cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Low back pain (LBP) is a frequent health complaint among health care personnel. Several work tasks and working postures are associated with an increased risk of LBP. The aim of this study was to compare two self-reported measures of physical demands and their association with LBP (the daily number of patient handling tasks and Hollmann's physical load index).</p> <p>Methods</p> <p>A questionnaire was distributed to 535 hospital employees in a psychiatric and an orthopedic ward in a Danish hospital. Of these 411 (77%) filled in and returned the questionnaire. Only the 373 respondents who had non-missing values on both measures of physical demands were included in the analyses. The distribution of physical demands in different job groups and wards are presented, variance analysis models are employed, and logistic regression analysis is used to analyze the association between measures of physical demands and LBP.</p> <p>Results</p> <p>In combination, hospital ward and job category explained 56.6% and 23.3% of the variance in the self-reported physical demands measured as the daily number of patient handling tasks and as the score on the physical load index, respectively. When comparing the 6% with the highest exposure the prevalence odds ratio (POR) for LBP was 5.38 (95% CI 2.03–14.29) in the group performing more than 10 patient handling tasks per day and 2.29 (95% CI 0.93–5.66) in the group with the highest score on the physical load index.</p> <p>Conclusion</p> <p>In specialized hospital wards the daily number of patient handling tasks seems to be a more feasible measure of exposure when assessing the risk of LBP compared to more advanced measures of physical load on the lower lumbar spine.</p

Effects of work ability and health promoting interventions for women with musculoskeletal symptoms: A 9-month prospective study

<p>Abstract</p> <p>Background</p> <p>Women working in the public human service sector in 'overstrained' situations run the risk of musculoskeletal symptoms and long-term sick leave. In order to maintain the level of health and work ability and strengthen the potential resources for health, it is important that employees gain greater control over decisions and actions affecting their health – a process associated with the concept of self-efficacy. The aim of this study was to describe the effects of a self-efficacy intervention and an ergonomic education intervention for women with musculoskeletal symptoms, employed in the public sector.</p> <p>Methods</p> <p>The design of the study was a 9-month prospective study describing the effects of two interventions, a comprehensive self-efficacy intervention (<it>n </it>= 21) and an ergonomic education intervention (<it>n </it>= 21). Data were obtained by a self-report questionnaire on health- and work ability-related factors at baseline, and at ten weeks and nine months follow-up. Within-group differences over time were analysed.</p> <p>Results</p> <p>Over the time period studied there were small magnitudes of improvements within each group. Within the self-efficacy intervention group positive effects in perceived work ability were shown. The ergonomic education group showed increased positive beliefs about future work ability and a more frequent use of pain coping strategies.</p> <p>Conclusion</p> <p>Both interventions showed positive effects on women with musculoskeletal symptoms, but in different ways. Future research in this area should tailor interventions to participants' motivation and readiness to change.</p

Two randomised and placebo-controlled studies of an oral prostacyclin analogue (Iloprost) in severe leg ischaemia [The Oral Iloprost in severe Leg Ischaemia Study Group]

Two separate studies are described using the same prostacyclin analogue in a similar group of patients. Objectives: to assess the tolerability and efficacy of two dose regimens of oral Iloprost compared with placebo in the treatment of patients with ischaemic ulcers, gangrene or rest pain due to severe arterial disease over a period of 4 weeks (Study A) and one year (Study B). Design: multicentre, placebo controlled, double-blind, randomized prospective studies. Subjects & Methods: 178 (study A) and 624 (study B) patients with trophic skin lesions (ulcers or gangrene) or ischaemic rest pain due to severe arterial disease. To confirm severe arterial disease patients were required to have a systolic ankle Doppler pressure of 70 mmHg or less or a toe systolic Doppler pressure of 50 mmHg or less in one leg.In both studies patients were randomly allocated to three treatment groups: placebo, low dose Iloprost (50\u2013100 g twice a day) or high dose (150\u2013200 g twice a day) In Study A the main outcome measures were tolerability of different doses of Iloprost and death, major amputation, healing of trophic lesions and relief of rest pain at the end of the follow up, which was 5 months after the end of the treatment. In Study B the primary end point was time to major amputation and stroke or death up to 12 months. Secondary pre-defined end points included the combined end point of patients alive without amputation, no trophic skin changes, no rest pain and not on regular analgesics. Results: the proportion of patients who completed the 4-week treatment period in Study A at the intended dose was 58%, 43%, 45% respectively in the placebo, low dose and high dose Iloprost groups. In an intention to treat analysis the proportion of patients who survived without major amputation, ulcers or gangrene and had no rest pain was 11% in the placebo group, 19% in the low dose iloprost group and 28% in the high dose Iloprost group. The pooled Iloprost groups showed a statistically significantly better result than the placebo group (p=0.04), as did the high dose Iloprost group compared to the placebo (p=0.014). In Study B there was no treatment benefit in terms of a primary end point of amputation and death. However the secondary combined end point of patients who survived without a major amputation, ulcers or gangrene and had no rest pain, nor a need for regular analgesia was favourable for Iloprost, with 18% of patients in the placebo group reaching this optimal secondary end point, compared to 23% in the low dose Iloprost group and 26% in the higher dose Iloprost group (p<0.05). Conclusions: oral Iloprost administered for a year showed no clear benefit in patients with advanced severe leg ischaemia (PAOD III and IV). The results obtained with 4 weeks\u2019 treatment in Study A and in previous trials of intravenous Iloprost could not be reproduce