443 research outputs found

    Design considerations for piezocomposite materials for electrical stimulation in medical implants

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Medical Engineering & Technology on 08 Jun 2022, available at: https://doi.org/10.1080/03091902.2022.2080881.Incidence of non-union following long bone fracture fixation and spinal fusion procedures is increasing, and very costly for patients and the medical system. Direct current (DC) electrical stimulation has shown success as an adjunct therapy to stimulate bone healing and increase surgery success rates, though drawbacks of current devices and implantable battery packs have limited widespread use. Energy harvesting utilising piezoelectric materials has been widely studied for powering devices without a battery, and a preclinical animal study has shown efficacy of a piezocomposite spinal fusion implant resulting in faster, more robust fusion. Most piezoelectric energy harvesters operate most effectively at high frequencies, limiting power generation from loads experienced by orthopaedic implants during human motion. This work characterises the efficient power generation capability of a novel composite piezoelectric material under simulated walking loads. Building on compliant layer adaptive composite stacks (CLACS), the power generation of mixed-mode CLACS (MMCLACS) is defined. Utilising poling direction to capitalise on in-plane strain generation due to compliant layer expansion, MMCLACS significantly increased power output compared to a standard piezo stack. The combination of radial and through-thickness poled piezoelectric elements within a stack to create MMCLACS significantly increases power generation under low-frequency dynamic loads. This technology can be adapted to a variety of architectures and assembled as a load-bearing energy harvester within current implants. MMCLACS integrated with implants would provide enough power to deliver bone healing electrical stimulation directly to the fusion site, decreasing non-union rates, and also could provide quantitative assessment of healing progression through load sensing

    Detection of Giardia and helminths in Western Europe at local K9 (canine) sites (DOGWALKS Study)

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    Background Intestinal parasite contamination from infected dogs can place other dogs and humans at risk. A study was initiated to estimate the prevalence of canine intestinal parasitism by collecting fecal samples in cities across Western Europe. Methods Fresh fecal samples were collected from 2469 dogs visiting 164 parks in 33 cities across 12 countries. Each owner responded to a questionnaire focusing on their dog‚Äôs signalment and recent anthelmintic treatment history. The collected samples were examined for hookworms, whipworms, ascarids and Giardia using a coproantigen diagnostic immunoassay and microscopy following centrifugal flotation. Results Nematodes or Giardia were detected in at least one sample from 100% of cities and in 93.3% of parks. Nematodes were detected in 57% of parks. Overall, 22.8% of dogs tested positive for an intestinal parasite, with Giardia being the most commonly identified parasites (17.3% of dogs, 83.5% of parks). For nematode infection, 7.6% of all dogs tested positive, with 9.9% of dogs aged‚ÄČ‚ÄČ1 month had passed since the previous dose. Conclusions The prevalence estimates of intestinal parasite infections in dogs reported here highlight the need for owner education concerning guidelines for regular testing and treatment, even in older dogs. Failure to adhere to guidelines can result in ongoing transmission of these infections, including those with zoonotic potential. Combining coproantigen immunoassay with centrifugal flotation for diagnostic testing and regular anthelmintic treatment are important measures for ensuring optimal intestinal parasite control

    Differential cross section measurements for the production of a W boson in association with jets in proton‚Äďproton collisions at ‚ąös = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript ‚ąí1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Juxtaposing BTE and ATE ‚Äď on the role of the European insurance industry in funding civil litigation