453 research outputs found

    Deceptive appearance of a normal variant of scaphoid bone in a teenage patient: a diagnostic challenge

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    Scaphoid fractures are a common injury in late teens and mid twenties with a peak period in skeletally immature children at about 15 years of age, although considered to be rare in first decade of life, its exact incidence in early teen age remains to be a subject of debate. We report an unusual case of anatomical variation of scaphoid bone at the level of waist which could potentially cause diagnostic confusion. A 14-years-old boy presented in the fracture clinic 2 weeks after injury to his Right wrist which was managed in a scaphoid cast. X-ray examinations, both at the time of injury and later on in the fracture clinic revealed features suspicious of a fracture at the level of waist of the scaphoid bone, however the clinical examination did not correlate with imaging, in view of that radiological imaging of the unaffected side was performed for comparison, which revealed it to be an anatomical variant of scaphoid at this age. To our knowledge there are very few cases of such variation reported in literature in this age group of patients. This case highlights the importance of anatomical variants in scaphoid bone in this age group, which might pose a diagnostic challenge and the need for appropriate management plan and reassurance to avoid unnecessary anxiety

    Noncirculant Toeplitz matrices all of whose powers are Toeplitz

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    summary:Let aa, bb and cc be fixed complex numbers. Let Mn(a,b,c)M_n(a,b,c) be the n×nn\times n Toeplitz matrix all of whose entries above the diagonal are aa, all of whose entries below the diagonal are bb, and all of whose entries on the diagonal are cc. For 1≤k≤n1\leq k\leq n, each k×kk\times k principal minor of Mn(a,b,c)M_n(a,b,c) has the same value. We find explicit and recursive formulae for the principal minors and the characteristic polynomial of Mn(a,b,c)M_n(a,b,c). We also show that all complex polynomials in Mn(a,b,c)M_n(a,b,c) are Toeplitz matrices. In particular, the inverse of Mn(a,b,c)M_n(a,b,c) is a Toeplitz matrix when it exists

    Orientational effects on the amplitude and phase of polarimeter signals in double resonance atomic magnetometry

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    Double resonance optically pumped magnetometry can be used to measure static magnetic fields with high sensitivity by detecting a resonant atomic spin response to a small oscillating field perturbation. Determination of the resonant frequency yields a scalar measurement of static field (B_0) magnitude. We present calculations and experimental data showing that the on-resonance polarimeter signal of light transmitted through an atomic vapour in arbitrarily oriented B0B_0 may be modelled by considering the evolution of alignment terms in atomic polarisation. We observe that the amplitude and phase of the magnetometer signal are highly dependent upon B_0 orientation, and present precise measurements of the distribution of these parameters over the full 4 pi solid angle

    A feed-forward measurement scheme for periodic noise suppression in atomic magnetometry

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    We present an unshielded, double-resonance magnetometer in which we have implemented a feed-forward measurement scheme in order to suppress periodic magnetic noise arising from, and correlated with, the mains electricity alternating current line. The technique described here uses a single sensor to track ambient periodic noise and feed forward to suppress it in a subsequent measurement. This feed forward technique has shown significant noise suppression of electrical mains-noise features of up to 22 dB under the fundamental peak at 50 Hz, 3 dB at the first harmonic (100 Hz), and 21 dB at the second harmonic (150 Hz). This technique is software based, requires no additional hardware, and is easy to implement in an existing magnetometer

    An Analysis of the Universal Home Care Program: Considerations for Implementation with the Context of Maine\u27s Existing LTSS Programs

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    A citizen initiative on the November 2018 ballot (Question 1, An Act to Establish Universal Home Care for Seniors and Persons with Disabilities) would establish a Universal Home Care Program (UHC Program) to serve older adults and persons with a disability living in Maine. This report does not constitute either support for or opposition to the referendum but is intended as an independent assessment of how the UHC Program could be implemented if it were to be approved by Maine voters. This analysis focuses on the implications of the UHC Program within the context of the Medicaid and state-funded long term services and supports programs currently administered by the Maine Department of Health and Human Services. The analysis assumes implementation would be guided by three goals: 1) avoiding an unintended negative impact on existing programs, 2) optimizing the use of public resources, and 3) advancing a community first model of care that promotes living at home when appropriate and preferred. This report does not address the financing or governance of the UHC Program as those are defined under the proposed legislation

    The Adhesive Capsulitis Corticosteroid and Dilation (ACCorD) randomized controlled trial.

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    AIMS: Is it feasible to conduct a definitive multicentre trial in community settings of corticosteroid injections (CSI) and hydrodilation (HD) compared to CSI for patients with frozen shoulder? An adequately powered definitive randomized controlled trial (RCT) delivered in primary care will inform clinicians and the public whether hydrodilation is a clinically and cost-effective intervention. In this study, prior to a full RCT, we propose a feasibility trial to evaluate recruitment and retention by patient and clinician willingness of randomization; rates of withdrawal, crossover and attrition; and feasibility of outcome data collection from routine primary and secondary care data. METHODS: In the UK, the National Institute for Health and Care Excellence (NICE) advises that prompt early management of frozen shoulder is initiated in primary care settings with analgesia, physiotherapy, and joint injections; most people can be managed without an operation. Currently, there is variation in the type of joint injection: 1) CSI, thought to reduce the inflammation of the capsule reducing pain; and 2) HD, where a small volume of fluid is injected into the shoulder joint along with the steroid, aiming to stretch the capsule of the shoulder to improve pain, but also allowing greater movement. The creation of musculoskeletal hubs nationwide provides infrastructure for the early and effective management of frozen shoulder. This potentially reduces costs to individuals and the wider NHS perhaps negating the need for a secondary care referral. RESULTS: We will conduct a multicentre RCT comparing CSI and HD in combination with CSI alone. Patients aged 18 years and over with a clinical diagnosis of frozen shoulder will be randomized and blinded to receive either CSI and HD in combination, or CSI alone. Feasibility outcomes include the rate of randomization as a proportion of eligible patients and the ability to use routinely collected data for outcome evaluation. This study has involved patients and the public in the trial design, dissemination methods, and how to include groups who are underserved by research. CONCLUSION: We will disseminate findings among musculoskeletal clinicians via the British Orthopaedic Association, the Chartered Society of Physiotherapy, the Royal College of Radiologists, and the Royal College of General Practitioners. To ensure wide reach we will communicate findings through our established network of charities and organizations, in addition to preparing dissemination findings in Bangla and Urdu (commonly spoken languages in northeast London). If a full trial is shown to be feasible, we will seek additional National Institute for Health and Care Research funding for a definitive RCT. This definitive study will inform NICE guidelines for the management of frozen shoulder

    Grating chips for quantum technologies

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    We have laser cooled3x10^6 87Rb atoms to 3uK in a micro-fabricated grating magneto-optical trap (GMOT), enabling future mass-deployment in highly accurate compact quantum sensors. We magnetically trap the atoms, and use Larmor spin precession for magnetic sensing in the vicinity of the atomic sample. Finally, we demonstrate an array of magneto-optical traps with a single laser beam, which will be utilised for future cold atom gradiometry

    Free-induction-decay magnetometer with enhanced optical pumping

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    Spin preparation prior to a free-induction-decay (FID) measurement can be adversely affected by transverse bias fields, particularly in the geophysical field range. A strategy that enhances the spin polarization accumulated before readout is demonstrated, by synchronizing optical pumping with a magnetic field pulse that supersedes any transverse fields by over two order of magnitude. The pulsed magnetic field is generated along the optical pumping axis using a compact electromagnetic coil pair encompassing a micro-electromechanical systems (MEMS) vapor cell. The coils also resistively heat the cesium (Cs) vapor to the optimal atomic density without spurious magnetic field contributions as they are rapidly demagnetized to approximately zero field during spin readout. The demagnetization process is analyzed electronically, and directly with a FID measurement, to confirm that the residual magnetic field is minimal during detection. The sensitivity performance of this technique is compared to existing optical pumping modalities across a wide magnetic field range. A noise floor sensitivity of 238 fT/√Hz238\,\mathrm{fT/\surd{Hz}} was achieved in a field of approximately 50 μT\mathrm{50\,\mu{T}}, in close agreement with the Cram\'{e}r-Rao lower bound (CRLB) predicted noise density of 258 fT/√Hz258\,\mathrm{fT/\surd{Hz}}.Comment: 10 pages, 7 figure

    An internet-based intervention with brief nurse support to manage obesity in primary care (POWeR+): a pragmatic, parallel-group, randomised controlled trial

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    Background The obesity epidemic has major public health consequences. Expert dietetic and behavioural counselling with intensive follow-up is effective, but resource requirements severely restrict widespread implementation in primary care, where most patients are managed. We aimed to estimate the effectiveness and cost-effectiveness of an internet-based behavioural intervention (POWeR+) combined with brief practice nurse support in primary care. Methods We did this pragmatic, parallel-group, randomised controlled trial at 56 primary care practices in central and south England. Eligible adults aged 18 years or older with a BMI of 30 kg/m2 or more (or ≥28 kg/m2 with hypertension, hypercholesterolaemia, or diabetes) registered online with POWeR+—a 24 session, web-based, weight management intervention lasting 6 months. After registration, the website automatically randomly assigned patients (1:1:1), via computer-generated random numbers, to receive evidence-based dietetic advice to swap foods for similar, but healthier, choices and increase fruit and vegetable intake, in addition to 6 monthly nurse follow-up (control group); web-based intervention and face-to-face nurse support (POWeR+Face-to-face [POWeR+F]; up to seven nurse contacts over 6 months); or web-based intervention and remote nurse support (POWeR+Remote [POWeR+R]; up to five emails or brief phone calls over 6 months). Participants and investigators were masked to group allocation at the point of randomisation; masking of participants was not possible after randomisation. The primary outcome was weight loss averaged over 12 months. We did a secondary analysis of weight to measure maintenance of 5% weight loss at months 6 and 12. We modelled the cost-effectiveness of each intervention. We did analysis by intention to treat, with multiple imputation for missing data. This trial is registered as an International Standard Randomised Controlled Trial, number ISRCTN21244703. Findings Between Jan 30, 2013, and March 20, 2014, 818 participants were randomly assigned to the control group (n=279), the POWeR+F group (n=269), or the POWeR+R group (n=270). Weight loss averaged over 12 months was recorded in 666 (81%) participants. The control group lost almost 3 kg over 12 months (crude mean weight: baseline 104·38 kg [SD 21·11; n=279], 6 months 101·91 kg [19·35; n=136], 12 months 101·74 kg [19·57; n=227]). The primary imputed analysis showed that compared with the control group, patients in the POWeR+F group achieved an additional weight reduction of 1·5 kg (95% CI 0·6–2·4; p=0·001) averaged over 12 months, and patients in the POWeR+R group achieved an additional 1·3 kg (0·34–2·2; p=0·007). 21% of patients in the control group had maintained a clinically important 5% weight reduction at month 12, compared with 29% of patients in the POWeR+F group (risk ratio 1·56, 0·96–2·51; p=0·070) and 32% of patients in the POWeR+R group (1·82, 1·31–2·74; p=0·004). The incremental overall cost to the health service per kg weight lost with the POWeR+ interventions versus the control strategy was £18 (95% CI −129 to 195) for POWeR+F and –£25 (−268 to 157) for POWeR+R; the probability of being cost-effective at a threshold of £100 per kg lost was 88% and 98%, respectively. No adverse events were reported. Interpretation Weight loss can be maintained in some individuals by use of novel written material with occasional brief nurse follow-up. However, more people can maintain clinically important weight reductions with a web-based behavioural program and brief remote follow-up, with no increase in health service costs. Future research should assess the extent to which clinically important weight loss can be maintained beyond 1 year

    Vector magnetometry exploiting phase-geometry effects in a double-resonance alignment magnetometer

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    Double-resonance optically pumped magnetometers are an attractive instrument for unshielded magnetic-field measurements due to their wide dynamic range and high sensitivity. The use of linearly polarized pump light creates alignment in the atomic sample, which evolves in the local static magnetic field, and is driven by a resonant applied field perturbation, modulating the polarization of transmitted light. We demonstrate experimentally that the amplitude and phase of observed first- and second-harmonic components in the transmitted polarization signal contain sufficient information to measure the static-magnetic-field magnitude and orientation. We describe a laboratory system for experimental measurements of these effects and verify a theoretical derivation of the observed signal. We demonstrate vector-field tracking under varying static-field orientations and show that the static-field magnitude and orientation may be observed simultaneously, with an experimentally realized resolution of 1.7 pT and 0.63 mrad in the most sensitive field orientation
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