85,602 research outputs found

    Physical therapies for reducing and controlling lymphoedema of the limbs.

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    Background Lymphoedema is the accumulation of excess fluid in the body caused by obstruction of the lymphatic drainage mechanisms. Management involves decongesting the reduced lymphatic pathways in order to reduce the size of the limb. There is a great deal of debate as to which components of a physical treatment programme are the most crucial. Objectives To assess the effect of physical treatment programmes on: volume, shape, condition and long-term control of oedema in lymphoedematous limbs; psycho-social benefits. Search strategy We searched the Cochrane Breast Cancer Group trials register (October 2007), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2008), MEDLINE, EMBASE, CINAHL and the National Research Register (February 2008) and UnCover, PASCAL, SIGLE, reference lists produced by The British Lymphology Society and The International Society of Lymphology congress proceedings (September 2003). Selection criteria Randomised controlled clinical trials that tested physical therapies with a follow-up period of at least six months. Data collection and analysis Two blinded reviewers independently assessed trial quality and extracted data . Meta-analysis was not performed due to the poor quality of the trials. Main results Only three studies involving 150 randomised patients were included. Since none studied the same intervention it was not possible to combine the data. One crossover study of manual lymph drainage (MLD) followed by self-administered massage versus no treatment, concluded that improvements seen in both groups were attributable to the use of compression sleeves and that MLD provided no extra benefit at any point during the trial. Another trial looked at hosiery versus no treatment and had a very high dropout rate, with only 3 out of 14 participants in the intervention group finishing the trial and only 1 out of 11 in the control group. The authors concluded that wearing a compression sleeve is beneficial. The bandage plus hosiery versus hosiery alone trial, concluded that in this mixed group of participants bandage plus hosiery resulted in a greater reduction in excess limb volume than hosiery alone and this difference in reduction was maintained long-term. Authors' conclusions All three trials have their limitations and have yet to be replicated, so their results must be viewed with caution. There is a clear need for well-designed, randomised trials of the whole range of physical therapies if the best approach to managing lymphoedema is to be determined

    Plate-impact loading of cellular structures formed by selective laser melting

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    Porous materials are of great interest because of improved energy absorption over their solid counterparts. Their properties, however, have been difficult to optimize. Additive manufacturing has emerged as a potential technique to closely define the structure and properties of porous components, i.e. density, strut width and pore size; however, the behaviour of these materials at very high impact energies remains largely unexplored. We describe an initial study of the dynamic compression response of lattice materials fabricated through additive manufacturing. Lattices consisting of an array of intersecting stainless steel rods were fabricated into discs using selective laser melting. The resulting discs were impacted against solid stainless steel targets at velocities ranging from 300 to 700 m s-1 using a gas gun. Continuum CTH simulations were performed to identify key features in the measured wave profiles, while 3D simulations, in which the individual cells were modelled, revealed details of microscale deformation during collapse of the lattice structure. The validated computer models have been used to provide an understanding of the deformation processes in the cellular samples. The study supports the optimization of cellular structures for application as energy absorbers. © 2014 IOP Publishing Ltd

    Hereditary model of loose mined rock layer deformation in disintegrators

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    The objective of this work is to substantiate the hereditary character of the stresses and deformations accumulation in loose mined rock during the disintegrators working surfaces convergence. It is shown, in particular, that the layer porosity after compression and the side thrust coefficient depend not only on the applied pressure, but also on the initial porosity. It is substantiated the mechanism of interrelation between the stresses and deformations of a layer. The experimental researches on fine– grained granite compression in a rigid matrix have been fulfilled. The approximation of obtained results by polynomial functions has been carried out. The coefficients have been determined by the least-square method. The close agreement of the analytical and the experimental values has been recorded. The initial porosity parameter was put into the equation of dependences of the current porosity and the side thrust coefficient on pressure. The mechanism of the forces distribution on separate particles contacts has been explained in terms of the material compacting hystory. The practical value of the research is in calculating the disintegrators operating parts parameters with account of the mined rock layer condition prior to the act of crushing

    Differential trends in the compression of mortality: Assessing the antecedents to current gaps in health expectancy in New Zealand

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    Health Expectancies (HEs) for New Zealand show significant differentials between Maori and non-Maori, but also by gender and period. These differentials correlate with findings from both generation and synthetic life-tables relating to New Zealand’s epidemiologic transition. At the beginning of that transition quartile 1 (Q(1)), and Median (Med) d(x) values were close and centred at young ages; during the transition the gap became very wide; at the transition’s end the gap again narrowed. Cohort and synthetic trends in d(x), l(x), M, Qs and Meds are reviewed and linked to recent HEs. Data point to epidemic polarisation. Cohort analysis allows the evaluation of the role of past experiences on the recent HEs, and thus point to possible strategies for reducing gaps in both d(x), and HEs

    On evolution of CMOS image sensors

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    CMOS Image Sensors have become the principal technology in majority of digital cameras. They started replacing the film and Charge Coupled Devices in the last decade with the promise of lower cost, lower power requirement, higher integration and the potential of focal plane processing. However, the principal factor behind their success has been the ability to utilise the shrinkage in CMOS technology to make smaller pixels, and thereby have more resolution without increasing the cost. With the market of image sensors exploding courtesy their inte- gration with communication and computation devices, technology developers improved the CMOS processes to have better optical performance. Nevertheless, the promises of focal plane processing as well as on-chip integration have not been fulfilled. The market is still being pushed by the desire of having higher number of pixels and better image quality, however, differentiation is being difficult for any image sensor manufacturer. In the paper, we will explore potential disruptive growth directions for CMOS Image sensors and ways to achieve the same
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