1,369 research outputs found
The Royal College of Ophthalmologists' National Ophthalmology Database study of cataract surgery: report 1, visual outcomes and complications.
Aim
To describe the outcomes of cataract surgery in the United Kingdom.
Methods
Anonymised data on 180â114 eyes from 127â685 patients undergoing cataract surgery between August 2006 and November 2010 were collected prospectively from 28 sites. Outcome measures included intraoperative and postoperative complication rates, and preoperative and postoperative visual acuities.
Results
Median age at first eye surgery was 77.1 years, 36.9% cases had ocular co-pathology and 41.0% patients underwent cataract surgery on both eyes. Preoperative visual acuity was 0.30 logMAR or better in 32.0% first eyes and 47.7% second eyes. Postoperative best-measured visual acuity was 0.00 and 0.30 logMAR or better in 50.8 and 94.6% eyes without ocular co-pathology, and 32.5 and 79.9% in eyes with co-pathology. For eyes without co-pathology, postoperative uncorrected distance visual acuity was 0.00 and 0.30 logMAR or better in 27.3 and 80.9% eyes. Posterior capsule rupture or vitreous loss or both occurred in 1.95% cases, and was associated with a 42 times higher risk of retinal detachment surgery within 3 months and an eight times higher risk of endophthalmitis.
Conclusion
These results provide updated data for the benchmarking of cataract surgery. Visual outcomes, and the rate of posterior capsule rupture or vitreous loss or both appear stable over the past decade
Virtual Biopsy in Soft Tissue Sarcoma. How Close Are We?
A shift in radiology to a data-driven specialty has been unlocked by synergistic developments in imaging biomarkers (IB) and computational science. This is advancing the capability to deliver "virtual biopsies" within oncology. The ability to non-invasively probe tumour biology both spatially and temporally would fulfil the potential of imaging to inform management of complex tumours; improving diagnostic accuracy, providing new insights into inter- and intra-tumoral heterogeneity and individualised treatment planning and monitoring. Soft tissue sarcomas (STS) are rare tumours of mesenchymal origin with over 150 histological subtypes and notorious heterogeneity. The combination of inter- and intra-tumoural heterogeneity and the rarity of the disease remain major barriers to effective treatments. We provide an overview of the process of successful IB development, the key imaging and computational advancements in STS including quantitative magnetic resonance imaging, radiomics and artificial intelligence, and the studies to date that have explored the potential biological surrogates to imaging metrics. We discuss the promising future directions of IBs in STS and illustrate how the routine clinical implementation of a virtual biopsy has the potential to revolutionise the management of this group of complex cancers and improve clinical outcomes
Spin- and energy relaxation of hot electrons at GaAs surfaces
The mechanisms for spin relaxation in semiconductors are reviewed, and the
mechanism prevalent in p-doped semiconductors, namely spin relaxation due to
the electron-hole exchange interaction, is presented in some depth. It is shown
that the solution of Boltzmann-type kinetic equations allows one to obtain
quantitative results for spin relaxation in semiconductors that go beyond the
original Bir-Aronov-Pikus relaxation-rate approximation. Experimental results
using surface sensitive two-photon photoemission techniques show that the spin
relaxation-time of electrons in p-doped GaAs at a semiconductor/metal surface
is several times longer than the corresponding bulk spin relaxation-times. A
theoretical explanation of these results in terms of the reduced density of
holes in the band-bending region at the surface is presented.Comment: 33 pages, 12 figures; earlier submission replaced by corrected and
expanded version; eps figures now included in the tex
Inventory control for point-of-use locations in hospitals
Most inventory management systems at hospital departments are characterised by lost sales, periodic reviews with short lead times, and limited storage capacity. We develop two types of exact models that deal with all these characteristics. In a capacity model, the service level is maximised subject to a capacity restriction, and in a service model the required capacity is minimised subject to a service level restriction. We also formulate approximation models applicable for any lost-sales inventory system (cost objective, no lead time restrictions etc). For the capacity model, we develop a simple inventory rule to set the reorder levels and order quantities. Numerical results for this inventory rule show an average deviation of 1% from the optimal service levels. We also embed the single-item models in a multi-item system. Furthermore, we compare the performance of fixed order size replenishment policies and (R, s, S) policies
Implementation of routine outcome measurement in child and adolescent mental health services in the United Kingdom: a critical perspective
The aim of this commentary is to provide an overview of clinical outcome measures that are currently recommended for use in UK Child and Adolescent Mental Health Services (CAMHS), focusing on measures that are applicable across a wide range of conditions with established validity and reliability, or innovative in their design. We also provide an overview of the barriers and drivers to the use of Routine Outcome Measurement (ROM) in clinical practice
Inhomogeneous isospin distribution in the reactions of 28Si + 112Sn and 124Sn at 30 and 50 MeV/nucleon
We have created quasiprojectiles of varying isospin via peripheral reactions
of 28Si + 112Sn and 124Sn at 30 and 50 MeV/nucleon. The quasiprojectiles have
been reconstructed from completely isotopically identified fragments. The
difference in N/Z of the reconstructed quasiprojectiles allows the
investigation of the disassembly as a function of the isospin of the
fragmenting system. The isobaric yield ratio 3H/3He depends strongly on N/Z
ratio of quasiprojectiles. The dependences of mean fragment multiplicity and
mean N/Z ratio of the fragments on N/Z ratio of the quasiprojectile are
different for light charged particles and intermediate mass fragments.
Observation of a different N/Z ratio of light charged particles and
intermediate mass fragments is consistent with an inhomogeneous distribution of
isospin in the fragmenting system.Comment: 5 pages, 4 Postscript figures, RevTe
Field-effect transistors assembled from functionalized carbon nanotubes
We have fabricated field effect transistors from carbon nanotubes using a
novel selective placement scheme. We use carbon nanotubes that are covalently
bound to molecules containing hydroxamic acid functionality. The functionalized
nanotubes bind strongly to basic metal oxide surfaces, but not to silicon
dioxide. Upon annealing, the functionalization is removed, restoring the
electronic properties of the nanotubes. The devices we have fabricated show
excellent electrical characteristics.Comment: 5 pages, 6 figure
The "0.4 eV" Shape Resonance of Electron Scattering from Mercury in a Franck-Hertz Tube
The alternative version of the Franck-Hertz experiment with mercury, in which
a two-grid tube is used as a combination of electron gun, equipotential
collision space, and detection cell, was analyzed recently in considerable
detail. In particular, it was inferred that, at optimal pressure, the formation
of peaks in the anode current at inelastic thresholds is mediated inside the
detection cell by the large variation, a maximum at 0.4 eV, in the cross
section for elastic scattering. This variation is due to a shape resonance in
the electron-mercury system and is observable persuasively at the onset of
anode current as a sharp peak followed by a clear minimum. In the present
paper, the passage of electrons through the second grid to anode region is
analyzed in terms of kinetic theory. The discussion is based on a simplified
expression for the electron current derivable from an approximate form of the
Boltzmann transport equation that maintains the spatial density gradient but
omits elastic energy losses. The estimated range of pressure underlying this
kind of idealization is in good agreement with experiment. An explicit solution
is obtained by constructing an analytic expression for the momentum transfer
cross section of mercury using a recent theory of generalized Fano profiles for
overlapping resonances. This solution is used in order to model successfully
the formation of peaks at the threshold of anode current and at excitation
potentials, and to explain the dependence of the observed profiles on the
pressure and on the sign and magnitude of the potential across the detection
cell
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Development of complex executive function over childhood: Longitudinal growth curve modeling of performance on the Groton Maze Learning Task
Supporting Information is available online at https://srcd.onlinelibrary.wiley.com/doi/10.1111/cdev.13888#support-information-section .Copyright © 2023 The Authors. This longitudinal study modeled children's complex executive function (EF) development using the Groton Maze Learning Task (GMLT). Using a cohort-sequential design, 147 children (61 males, 5.5â11âyears) were recruited from six multicultural primary schools in Melbourne and Perth, Australia. Race/ethnicity data were not available. Children were assessed on the GMLT at 6-month intervals over 2-years between 2010 and 2012. Growth curve models describe age-related change from 5.5 to 12.5âyears old. Results showed a quadratic growth trajectory on each measure of errorâthat is, those that reflect visuospatial memory, executive control (or the ability to apply rules for action), and complex EF. The ability to apply rules for action, while a rate-limiting factor in complex EF, develops rapidly over early-to-mid childhood.Australian Research Council. Grant Number: DP1094535; Open access publishing facilitated by Australian Catholic University, as part of the Wiley - Australian Catholic University agreement via the Council of Australian University Librarians
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