561 research outputs found

    Developing ODP student placements

    Get PDF
    In a similar way to nursing and other health professions, elements of the education of operating department practitioners (ODPs) can only be contextualised by clinical practice involvement (Stockhausen and Strutt, 2005; Higginson, 2006; Morgan, 2006). The importance of high-quality placement experiences for all UK health professions is widely acknowledged (Quality Assurance Agency, 2001). Prior to 2009, students on the Diploma in Higher Education ODP programme undertook four clinical placements in the same Trust or organisation. At the time of the project there was a shortfall in the number of placements available and, although the university explored placing students in different clinical areas, such as private healthcare providers and new areas in the NHS, none could provide the full learning experience for students to achieve the required competencies. The course team developed a system that uses placements in a variety of settings and ensures students can gain the required outcomes. The new approach involves auditing for individual placements, instead of for the full course duration. Students are now informed throughout recruitment and selection events that they should be undertaking placements in a minimum of three different organisations. Students now move to a different organisation with every experience, to gain a variety of clinical knowledge. This has resulted in the greater use of clinical placements and the development of new areas for students to gain experience. The benefits of students’ experiences have increased, as they can develop skills and understanding of the ODP role from different perspectives

    Ultra-fast sampling of terahertz pulses from a quantum cascade laser using superconducting antenna-coupled NbN and YBCO detectors

    Get PDF
    We demonstrate the ultra-fast detection of terahertz pulses from a quantum cascade laser (QCL) using superconducting NbN and YBCO detectors. This has enabled both the intrapulse and interpulse dynamics of a THz QCL to be measured directly, including interpulse heating effects on sub-μs timescales

    Novel Li3ClO based glasses with superionic properties for lithium batteries

    Get PDF
    Three types of next generation batteries are currently being envisaged among the international community: metal-air batteries, multivalent cation batteries and all-solid-state batteries. These battery designs require high-performance, safe and cost effective electrolytes that are compatible with optimized electrode materials. Solid electrolytes have not yet been extensively employed in commercial batteries as they suffer from poor ionic conduction at acceptable temperatures and insufficient stability with respect to lithium-metal. Here we show a novel type of glasses, which evolve from an antiperovskite structure and that show the highest ionic conductivity ever reported for the Li-ion (25 mS cm-1 at 25 °C). These glassy electrolytes for lithium batteries are inexpensive, light, recyclable, non-flammable and non-toxic. Moreover, they present a wide electrochemical window (higher than 8 V) and thermal stability within the application range of temperatures

    Mechanical Competence and Bone Quality Develop During Skeletal Growth.

    Get PDF
    Bone fracture risk is influenced by bone quality, which encompasses bone's composition as well as its multiscale organization and architecture. Aging and disease deteriorate bone quality, leading to reduced mechanical properties and higher fracture incidence. Largely unexplored is how bone quality and mechanical competence progress during longitudinal bone growth. Human femoral cortical bone was acquired from fetal (n = 1), infantile (n = 3), and 2- to 14-year-old cases (n = 4) at the mid-diaphysis. Bone quality was assessed in terms of bone structure, osteocyte characteristics, mineralization, and collagen orientation. The mechanical properties were investigated by measuring tensile deformation at multiple length scales via synchrotron X-ray diffraction. We find dramatic differences in mechanical resistance with age. Specifically, cortical bone in 2- to 14-year-old cases exhibits a 160% greater stiffness and 83% higher strength than fetal/infantile cases. The higher mechanical resistance of the 2- to 14-year-old cases is associated with advantageous bone quality, specifically higher bone volume fraction, better micronscale organization (woven versus lamellar), and higher mean mineralization compared with fetal/infantile cases. Our study reveals that bone quality is superior after remodeling/modeling processes convert the primary woven bone structure to lamellar bone. In this cohort of female children, the microstructural differences at the femoral diaphysis were apparent between the 1- to 2-year-old cases. Indeed, the lamellar bone in 2- to 14-year-old cases had a superior structural organization (collagen and osteocyte characteristics) and composition for resisting deformation and fracture than fetal/infantile bone. Mechanistically, the changes in bone quality during longitudinal bone growth lead to higher fracture resistance because collagen fibrils are better aligned to resist tensile forces, while elevated mean mineralization reinforces the collagen scaffold. Thus, our results reveal inherent weaknesses of the fetal/infantile skeleton signifying its inferior bone quality. These results have implications for pediatric fracture risk, as bone produced at ossification centers during children's longitudinal bone growth could display similarly weak points. © 2019 American Society for Bone and Mineral Research

    A comparison of community and trophic structure in five marine ecosystems based on energy budgets and system metrics

    Get PDF
    As part of the international MENU collaboration, energy budget models for five marine ecosystems were compared to identify differences and similarities in trophic and community characteristics across ecosystems. We examined the Gulf of Maine and Georges Bank in the Northwest Atlantic Ocean, the combined Norwegian/Barents Seas in the Northeast Atlantic Ocean, and the eastern Bering Sea and the Gulf of Alaska in the Northeast Pacific Ocean. Comparable energy budgets were constructed for each ecosystem by aggregating information for similar species groups into consistent functional groups across all five ecosystems. Several ecosystem metrics (including functional group production, consumption, and biomass ratios, ABC curves, cumulative biomass, food web macrodescriptors, and network metrics) were examined across the ecosystems. The comparative approach clearly identified data gaps for each ecosystem, an important outcome of this work. Commonalities across the ecosystems included overall high primary production and energy flow at low trophic levels, high production and consumption by carnivorous zooplankton, and similar proportions of apex predator to lower trophic level biomass. Major differences included distinct biomass ratios of pelagic to demersal fish, ranging from highest in the Norwegian/Barents ecosystem to lowest in the Alaskan systems, and notable gradients in primary production per unit area, highest in the Alaskan and Georges Bank/Gulf of Maine ecosystems, and lowest in the Norwegian ecosystems. While comparing a disparate group of organisms across a wide range of marine ecosystems is challenging, this work demonstrates that standardized metrics both elucidate properties common to marine ecosystems and identify key distinctions for fishery management

    Re-structuring of marine communities exposed to environmental change

    Get PDF
    Species richness is the most commonly used but controversial biodiversity metric in studies on aspects of community stability such as structural composition or productivity. The apparent ambiguity of theoretical and experimental findings may in part be due to experimental shortcomings and/or heterogeneity of scales and methods in earlier studies. This has led to an urgent call for improved and more realistic experiments. In a series of experiments replicated at a global scale we translocated several hundred marine hard bottom communities to new environments simulating a rapid but moderate environmental change. Subsequently, we measured their rate of compositional change (re-structuring) which in the great majority of cases represented a compositional convergence towards local communities. Re-structuring is driven by mortality of community components (original species) and establishment of new species in the changed environmental context. The rate of this re-structuring was then related to various system properties. We show that availability of free substratum relates negatively while taxon richness relates positively to structural persistence (i.e., no or slow re-structuring). Thus, when faced with environmental change, taxon-rich communities retain their original composition longer than taxon-poor communities. The effect of taxon richness, however, interacts with another aspect of diversity, functional richness. Indeed, taxon richness relates positively to persistence in functionally depauperate communities, but not in functionally diverse communities. The interaction between taxonomic and functional diversity with regard to the behaviour of communities exposed to environmental stress may help understand some of the seemingly contrasting findings of past research

    First principles calculations and experiments for Cu-Mg/Li hydrides negative electrodes

    Get PDF
    We have studied CuLi0.08Mg1.92 and determined that the compound reacts with hydrogen to form CuLi0.08Mg 1.92H5 [1]. Additionally, we have proposed the compound as a negative electrode material which is the main purpose of the present study. Moreover, we have observed that the latter compound acts as a catalyst in the formation of MgH2, LiH, TiH2 [2] and hydrogen desorption. In this work, first principles and phonon calculations were performed in order to establish the reactions occurring at the negative electrode of a Li conversion battery in presence of CuLi0.08Mg1.92H 5 and (Li) - solid solution of Mg in Li - Approximately Li 2Mg3. We have calculated the minimum theoretical specific capacity to be 1156 mAh/g (for an anode with 100% of CuLi0.08Mg 1.92H5) and the Eeq = 0.81 V (vs. Li+/Li) at 298 K. Furthermore, we have determined all the reactions occurring in the referred system and its sequence using Inelastic Incoherent Neutron Scattering (TINS) and X-Ray Diffraction (XRD). (c) 2013 Materials Research Society

    Aluminium content of spanish infant formula

    Get PDF
    Aluminium toxicity has been relatively well documented in infants with impaired renal function and premature neonates. The aims of this study were to analyse the concentration of aluminium in the majority of infant formulae sold commercially in Spain, to determine the influence of aluminium content in the tap water in reconstituted powder formulae and to estimate the theoretical toxic aluminium intake in comparison with the PTWI, and lastly, to discuss the possible interactions of certain essential trace elements added to formulation with aluminium according to type or main protein based infant formula. A total of 82 different infant formulae from 9 different manufacturers were studied. Sample digestion was simulated in a closed acid-decomposition microwave system. Aluminium concentration was determined by atomic absorption spectrophotometry with graphite furnace. In general, the infant formulae studied provide an aluminium level higher than that found in human milk, especially in the case of soya, preterm or hydrolysed casein-based formulae. Standard formulae provide lower aluminium intakes amounting to about 4 % PTWI. Specialised and preterm formulae result in moderate intake (11 – 12 % and 8 – 10 % PTWI, respectively). Soya formulae contribute the highest intake (15 % PTWI). Aluminium exposure from drinking water used for powder formula reconstitution is not considered a clear potential risk. In accordance with the present state of knowledge about aluminium toxicity, it seems prudent to call for continued efforts to standardise routine quality control and reduce aluminium levels in infant formula as well as to keep the aluminium concentration under 300 g l-1 for all infant formulae, most specifically those formulae for premature and low birth neonates

    Intra-pulse transition between ion acceleration mechanisms in intense laser-foil interactions

    Get PDF
    Multiple ion acceleration mechanisms can occur when an ultrathin foil is irradiated with an intense laser pulse, with the dominant mechanism changing over the course of the interaction. Measurement of the spatial-intensity distribution of the beam of energetic protons is used to investigate the transition from radiation pressure acceleration to transparency-driven processes. It is shown numerically that radiation pressure drives an increased expansion of the target ions within the spatial extent of the laser focal spot, which induces a radial deflection of relatively low energy sheath-accelerated protons to form an annular distribution. Through variation of the target foil thickness, the opening angle of the ring is shown to be correlated to the point in time transparency occurs during the interaction and is maximized when it occurs at the peak of the laser intensity profile. Corresponding experimental measurements of the ring size variation with target thickness exhibit the same trends and provide insight into the intra-pulse laser-plasma evolution
    corecore