629 research outputs found
Evaluation of the Cementation Index as a Predictor of Failure in Total Elbow Arthroplasty
Background. The aim of this study is to objectively evaluate the quality of cementation by a novel method called the cementation index and assess its utility as a predictor of failure. Materials and Methods. Fifty elbows with primary Coonrad-Morrey total elbow replacement were included. The quality of cementing was assessed by novel methods, the vertical and horizontal cementation index, which were statistically evaluated as predictors of failure. The mean period of followup was 8.08±2.95 years (range: from 5.08 to 10.25 years). Results. The mean vertical cementation index of the humerus (vCIH) was 1.22 ± 0.28 and that of the ulna (vCIU) was 1.10±0.18. Radiolucent zones were noted in two cases in the humerus with a horizontal cementation index of 0.21 and 0.14, respectively. Both of the cementation indices were not found to be statistically significant predictors of failure (P>0.05). The five-year survival rate was 94%. Discussion and Conclusion. The cementation index, being a ratio, reduces the confounding effect of taking radiographs in different positions of the limb with different magnification in followup radiographs. It is an easy and objective method of assessment of cementation, the results of which need to be validated by a larger study
High Photovoltaic Quantum Efficiency in Ultrathin van der Waals Heterostructures
We report experimental measurements for ultrathin (< 15 nm) van der Waals
heterostructures exhibiting external quantum efficiencies exceeding 50%, and
show that these structures can achieve experimental absorbance > 90%. By
coupling electromagnetic simulations and experimental measurements, we show
that pn WSe2/MoS2 heterojunctions with vertical carrier collection can have
internal photocarrier collection efficiencies exceeding 70%.Comment: ACS Nano, 2017. Manuscript (25 pages, 7 figures) plus supporting
information (7 pages, 4 figures
Electrical Control of Linear Dichroism in Black Phosphorus from the Visible to Mid-Infrared
The incorporation of electrically tunable materials into photonic structures
such as waveguides and metasurfaces enables dynamic control of light
propagation by an applied potential. While many materials have been shown to
exhibit electrically tunable permittivity and dispersion, including transparent
conducting oxides (TCOs) and III-V semiconductors and quantum wells, these
materials are all optically isotropic in the propagation plane. In this work,
we report the first known example of electrically tunable linear dichroism,
observed here in few-layer black phosphorus (BP), which is a promising
candidate for multi-functional, broadband, tunable photonic elements. We
measure active modulation of the linear dichroism from the mid-infrared to
visible frequency range, which is driven by anisotropic quantum-confined Stark
and Burstein-Moss effects, and field-induced forbidden-to-allowed optical
transitions. Moreover, we observe high BP absorption modulation strengths,
approaching unity for certain thicknesses and photon energies
Near-Unity Absorption in van der Waals Semiconductors for Ultrathin Optoelectronics
We demonstrate near-unity, broadband absorbing optoelectronic devices using sub-15 nm thick transition metal dichalcogenides (TMDCs) of molybdenum and tungsten as van der Waals semiconductor active layers. Specifically, we report that near-unity light absorption is possible in extremely thin (<15 nm) van der Waals semiconductor structures by coupling to strongly damped optical modes of semiconductor/metal heterostructures. We further fabricate Schottky junction devices using these highly absorbing heterostructures and characterize their optoelectronic performance. Our work addresses one of the key criteria to enable TMDCs as potential candidates to achieve high optoelectronic efficiency
Aligning everyday life priorities with people's self-management support networks: an exploration of the work and implementation of a needs-led telephone support system
Background: Recent initiatives to target the personal, social and clinical needs of people with long-term health conditions have had limited impact within primary care. Evidence of the importance of social networks to support people with long-term conditions points to the need for self-management approaches which align personal circumstances with valued activities. The Patient-Led Assessment for Network Support (PLANS) intervention is a needs-led assessment for patients to prioritise their health and social needs and provide access to local community services and activities. Exploring the work and practices of patients and telephone workers are important for understanding and evaluating the workability and implementation of new interventions.
Methods: Qualitative methods (interviews, focus group, observations) were used to explore the experience of PLANS from the perspectives of participants and the telephone support workers who delivered it (as part of an RCT) and the reasons why the intervention worked or not. Normalisation Process Theory (NPT) was used as a sensitising tool to evaluate: the relevance of PLANS to patients (coherence); the processes of engagement (cognitive participation); the work done for PLANS to happen (collective action); the perceived benefits and costs of PLANS (reflexive monitoring). 20 patients in the intervention arm of a clinical trial were interviewed and their telephone support calls were recorded and a focus group with 3 telephone support workers was conducted.
Results: Analysis of the interviews, support calls and focus group identified three themes in relation to the delivery and experience of PLANS. These are: formulation of ‘health’ in the context of everyday life; trajectories and tipping points: disrupting everyday routines; precarious trust in networks. The relevance of these themes are considered using NPT constructs in terms of the work that is entailed in engaging with PLANS, taking action, and who is implicated this process.
Conclusions: PLANS gives scope to align long-term condition management to everyday life priorities and valued aspects of life. This approach can improve engagement with health-relevant practices by situating them within everyday contexts. This has potential to increase utilisation of local resources with potential cost-saving benefits for the NH
Multiple Current States of Two Phase-Coupled Superconducting Rings
The states of two phase-coupled superconducting rings have been investigated.
Multiple current states have been revealed in the dependence of the critical
current on the magnetic field. The performed calculations of the critical
currents and energy states in a magnetic field have made it possible to
interpret the experiment as the measurement of energy states into which the
system comes with different probabilities because of the equilibrium and
non-equilibrium noises upon the transition from the resistive state to the
superconducting state during the measurement of the critical currentComment: 5 pages, 5 figure
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