42 research outputs found
Effects of low dose morphine on perceived sleep quality in patients with refractory breathlessness : a hypothesis generating study
© 2015 Asian Pacific Society of Respirology. Background and objective The management of chronic refractory breathlessness is one of the indications for regular low-dose (â€30 mg/24 h) oral sustained release morphine. Morphine may disrupt sleep in some conditions and improve sleep quality in others. This study aimed to determine any signal of regular, low-dose morphine on perceived sleep disruption due to breathlessness and perceived sleep quality. Methods This is a secondary analysis of data from 38 participants with refractory breathlessness (30 male; 33 with COPD) aged 76 ± 0.9 years who completed a double-blind, randomized, placebo-controlled, cross-over study in which they received 20 mg oral sustained release morphine daily and placebo for 4 days each. Participant ratings of sleep disruption due to breathlessness and perceived sleep quality were obtained daily throughout the 8-day trial. Results Perceived sleep disruption due to breathlessness over the 4-day period ranged between 13% and 32% of participants for placebo and 13% and 26% for morphine, decreasing by each day of the study during the morphine arm. Most participants reported 'very good' or 'quite good' sleep throughout the trial and were less likely to perceive poor sleep quality during the morphine arm (odds ratio = 0.55, 95% confidence interval: 0.34-0.88, P = 0.01). Participants who reported decreased breathlessness during the 4 days on morphine were also likely to report improved sleep quality with morphine (P = 0.039). Conclusion Four days of low-dose morphine improved perceived sleep quality in elderly participants with refractory breathlessness. Regular low-dose morphine targeted to reduce refractory breathlessness may yield associated benefits by reducing sleep disruption and improving sleep quality
Magnetic properties of (FeCo)B alloys and the effect of doping by 5 elements
We have explored, computationally and experimentally, the magnetic properties
of \fecob{} alloys. Calculations provide a good agreement with experiment in
terms of the saturation magnetization and the magnetocrystalline anisotropy
energy with some difficulty in describing CoB, for which it is found that
both full potential effects and electron correlations treated within dynamical
mean field theory are of importance for a correct description. The material
exhibits a uniaxial magnetic anisotropy for a range of cobalt concentrations
between and . A simple model for the temperature dependence of
magnetic anisotropy suggests that the complicated non-monotonous temperature
behaviour is mainly due to variations in the band structure as the exchange
splitting is reduced by temperature. Using density functional theory based
calculations we have explored the effect of substitutional doping the
transition metal sublattice by the whole range of 5 transition metals and
found that doping by Re or W elements should significantly enhance the
magnetocrystalline anisotropy energy. Experimentally, W doping did not succeed
in enhancing the magnetic anisotropy due to formation of other phases. On the
other hand, doping by Ir and Re was successful and resulted in magnetic
anisotropies that are in agreement with theoretical predictions. In particular,
doping by 2.5~at.\% of Re on the Fe/Co site shows a magnetocrystalline
anisotropy energy which is increased by 50\% compared to its parent
(FeCo)B compound, making this system interesting, for
example, in the context of permanent magnet replacement materials or in other
areas where a large magnetic anisotropy is of importance.Comment: 15 pages 17 figure
Toward Rare-Earth-Free Permanent Magnets: A Combinatorial Approach Exploiting the Possibilities of Modeling, Shape Anisotropy in Elongated Nanoparticles, and Combinatorial Thin-Film Approach
The objective of the rare-earth free permanent magnets (REFREEPM) project is to develop a new generation of high-performance permanent magnets (PMs) without rare earths. Our approach is based on modeling using a combinatorial approach together with micromagnetic modeling and the realization of the modeled systems (I) by using a novel production of high-aspect-ratio (>5) nanostructrures (nanowires, nanorods, and nanoflakes) by exploiting the magnetic shape anisotropy of the constituents that can be produced via chemical nanosynthesis polyol process or electrodeposition, which can be consolidated with novel processes for a new generation of rare-earth free PMs with energy product in the range of 60 kJ/m3 < (BH)max < 160 kJ/m3 at room temperature, and (II) by using a high-throughput thin-film synthesis and high-throughput characterization approach to identify promising candidate materials that can be stabilized in a tetragonal or hexagonal structure by epitaxial growth on selected substrates, under various conditions of pressure, stoichiometry, and temperature. In this article, we report the progress so far in selected phases.This work is supported by European Commission (REFREEPERMAG project) grant number GA-NMP3-SL-2012-280670
Sex, age, deprivation and patterns in life expectancy in Quebec, Canada: a population-based study
<p>Abstract</p> <p>Background</p> <p>Little research has evaluated disparities in life expectancy according to material deprivation taking into account differences across the lifespan between men and women. This study investigated age- and sex-specific life expectancy differentials related to area-level material deprivation for the province of Québec, Canada from 1989-2004.</p> <p>Methods</p> <p>Age- and sex-specific life expectancy across the lifespan was calculated for three periods (1989-1992, 1995-1998, and 2001-2004) for the entire Québec population residing in 162 community groupings ranked according to decile of material deprivation. Absolute and relative measures were calculated to summarize differences between the most and least deprived deciles.</p> <p>Results</p> <p>Life expectancy differentials between the most and least deprived deciles were greatest for men. Over time, male differentials increased for age 20 or more, with little change occurring at younger ages. For women, differentials increased across the lifespan and were comparable to men at advanced ages. Despite gains in life expectancy among men relative to women, differentials between men and women were greater for most deprived relative to least deprived deciles.</p> <p>Conclusions</p> <p>Similar to the US, differentials in life expectancy associated with area-level material deprivation increased steadily in Québec from 1989-2004 for males and females of all ages. Differentials were comparable between men and women at advanced ages. Previous research indicating that life expectancy differentials between most and least deprived areas are greater in men may be due to a focus on younger age groups.</p
Establishing the acute physiological and sleep disruption characteristics of wind farm versus road traffic noise disturbances in sleep: a randomized controlled trial protocol
Advance access publication 6 September 2023Study Objectives: Despite the global expansion of wind farms, effects of wind farm noise (WFN) on sleep remain poorly understood. This protocol details a randomized controlled trial designed to compare the sleep disruption characteristics of WFN versus road traffic noise (RTN). Methods: This study was a prospective, seven night within-subjects randomized controlled in-laboratory polysomnography-based trial. Four groups of adults were recruited from; 15 s events) from sleep by each noise type with acute (20-s) and more sustained (3-min) noise exposures. Secondary analyses will compare doseâresponse effects of sound pressure level and noise type on EEG K-complex probabilities and quantitative EEG measures, and cardiovascular activation responses. Group effects, self-reported noise sensitivity, and wake versus sleep noise exposure effects will also be examined. Conclusions: This study will help to clarify if wind farm noise has different sleep disruption characteristics compared to road traffic noise.Gorica Micic, Branko Zajamsek, Bastien Lechat, Kristy Hansen, Hannah Scott, Barbara Toson, Tessa Liebich, Claire Dunbar, Duc Phuc Nguyen, Felix Decup, Andrew Vakulin, Nicole Lovato, Leon Lack, Colin Hansen, Dorothy Bruck, Ching Li Chai-Coetzer, Jeremy Mercer, Con Doolan and Peter Catchesid
Particle-Level Residence Time Data in a Twin-Screw Feeder
Pre-processed particle data obtained from DEM simulations. For each particle, the initial position in the twin-screw feeder, the particle radius, and the residence time is given. The data is available for 3 fill levels in the feeder (100%, 66%, 40%). Included in the dataset are example RTDs obtained from the particle data, a minimum working example for a Python script that calculates the RTD of particles in two spatial regions of the feeder, and a video of the complete discharge process rendered from the DEM results
Particle-Level Residence Time Data in a Twin-Screw Feeder
Pre-processed particle data obtained from DEM simulations. For each particle, the initial position in the twin-screw feeder, the particle radius, and the residence time is given. The data is available for 3 fill levels in the feeder (100%, 66%, 40%). Included in the dataset are example RTDs obtained from the particle data, a minimum working example for a Python script that calculates the RTD of particles in two spatial regions of the feeder, and a video of the complete discharge process rendered from the DEM results.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
Modelling of Packed Co Nanorods for Hard Magnetic Applications
We present a numerical algorithm based on the bullet physics library to generate densely packed (39% - 41%) structures of high-aspect-ratio nanorods for finite element micromagnetic simulations. The coercivities ”0Hc of the corresponding Cobalt nanorod structures vary between 0.50T and 0.67T, depending on the overall orientation of nanorods, which is in good agreement with experimental results. The simulations make it possible to estimate the coercivity loss due to incoherent reversal processes (27%) as well as the gain due to shape anisotropy (59%). Our calculations show permanent magnets consisting of packed Co nanorods with an energy density product (BH)max of 83kJ/m3. We estimate that this value can be increased to 103kJ/m3 by increasing the packing density from 40% to 45%. Another way to optimize (BH)max is the usage of novel materials. By varying the anisotropy constant K1 and the saturation polarisation JS we found lower limits for these parameters to reach a certain energy density product. To increase (BH)max to 160 kJ/m3, K1 and JS have to be in the order of 450kJ/m3 and 2.25T, respectively. The thermal stability of this approach was verified by elastic band calculations. Cobalt nanorods with a diameter of 10nm and a height of 50nm are thermally stable at room temperature, but problematic at 900K. Doubling the nanorods' height to 100nm increases that limit considerably