701 research outputs found

    Utility of Ultrasound for Imaging Osteophytes in Patients with Insertional Achilles Tendinopathy

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    Objectives: To examine (1) the validity of ultrasound imaging to measure osteophytes and (2) the association between osteophytes and insertional Achilles tendinopathy (IAT). Design: Case-control study. Setting: Academic medical center. Participants: Persons with chronic unilateral IAT (n=20; mean age, 58.7±8.3y; 10 [50%] women) and age- and sex-matched controls (n=20; mean age, 57.4±9.8y; 10 [50%] women) participated in this case-control study (N=40). Interventions: Not applicable. Main Outcome Measures: Symptom severity was assessed using the Foot and Ankle Ability Measure, the Victorian Institute of Sport Assessment-Achilles questionnaire, and the numerical rating scale. Length of osteophytes was measured bilaterally in both groups using ultrasound imaging, as well as on the symptomatic side of the IAT group using radiography. The intraclass correlation coefficient was used to examine the agreement between ultrasound and radiograph measures. McNemar, Wilcoxon signed-rank, and Fisher exact tests were used to compare the frequency and length of osteophytes between sides and groups. Pearson correlation was used to examine the association between osteophyte length and symptom severity. Results: There was good agreement (intraclass correlation coefficient, ≥.75) between ultrasound and radiograph osteophyte measures. There were no statistically significant differences (P\u3e.05) in the frequency of osteophytes between sides or groups. Osteophytes were larger on the symptomatic side of the IAT group than on the asymptomatic side (P=.01) and on the left side of controls (P=.03). There was no association between osteophyte length and symptom severity. Conclusions: Ultrasound imaging is a valid measure of osteophyte length, which is associated with IAT. Although a larger osteophyte indicates tendinopathy, it does not indicate more severe IAT symptoms

    Multimode Dispersion Compensated Pulse-Echo Guided Wave Inspection

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    Obtaining temporal/spatial resolution in guided wave measurements comparable to that of bulk wave measurements is impeded by the complicating effects of multimode dispersion. Transport of signals by multiple dispersive modes of propagation can transform an initially compact transient into an extended, visually unintelligible wavetrain. Guided mode inspections therefore tend to restrict measurements to regimes for which a single mode can be generated with minimal dispersion, consequently restricting the achievable temporal/spatial resolution of the measurement. The objective of the work reported here is to remove such restrictions, through implementation of wavefield measurements which accommodate the total complexity of multimode dispersed signals. Temporal and spatial Fourier analysis of guided wave fields enables a full identification of individual mode contributions. It is therefore conceivable that, given measurements taken over an appropriate spatial array, processing could be implemented to effectively remove the effects of multimode dispersion, enabling operation in frequency regimes currently associated with bulk wave measurements. This paper will report on work which is exploring this possibility. Results will be presented demonstrating array-based MHz regime plate wave measurements, generating 10 or more modes, in which individual modes are isolated, effects of dispersion are removed, and temporal resolution of the original transmitted pulse is restored. Examples of application will be presented, and factors determining the effectiveness of temporal resolution restoration will be discussed

    The Influence of Thin Bonding Layers on the Leaky Waves at Liquid-Solid Interfaces

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    This paper presents theoretical and experimental results on the problem of bounded acoustic beam reflection at the Rayleigh angle from a fluid-solid interface which is loaded by a thin solid layer. The theoretical development exploits the framework of existing theory to yield a simple, analytic model which is reasonably accurate for thin layers. It is shown that the influence of the layer is contained entirely in the dispersive Rayleigh wavespeed and the thickness-dependent displacement parameter Δs. Measurements of the reflected acoustic field amplitude have been performed on several samples of stainless steel loaded with a thin copper layer. We have found reasonably good agreement between the theoretical model calculations and experimental measurements for ratios of the layer thickness to the Rayleigh wavelength as large as 0.3. Beyond this value, some disparity is observed, particularly in the calculation of the thickness-dependent Rayleigh wavespeed

    MOSAIC: A Scalable reconfigurable 2D array system for NDT

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    This paper documents the development of a scalable 2D array system, or Mosaic that can be targeted at a wide range of NDT applications by way of a reconfigurable tile that can be tessellated to form arrays of any size and shape. Close coupling permits utilization of excitation voltages as low as +/-3.3V with insertion loss of 48dB on reflection from an aluminum back wall at 73mm achieved using 2D arrays without decoding

    Long-term ustekinumab therapy of psoriasis in patients with coexisting rheumatoid arthritis and Sjögren syndrome. Report of two cases and review of literature

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    Background: Inteleukin (IL)12 and IL23 are two main cytokines involved in the pathogenesis of immune-mediated disease. IL12 is produced by macrophages and B lymphocytes and mediates differentiation of Th1 lymphocytes, while IL23 is a pro-inflammatory cytokine essential for the differentiation of Th17 cells. Ustekinumab is a human monoclonal antibody directed against the p40 protein subunit shared by IL12 and IL23, therefore it blocks the signal transmission of both cytokines. Main observations: We present two cases and discuss the long-term efficacy of ustekinumab as a treatment of psoriasis in patients affected by autoimmune diseases, rheumatoid arthritis and Sjögren’s syndrome, who presented with severe psoriasis after anti-TNF treatment. Conclusions: To the best of our knowledge, these are the first cases reported in the literature describing the long-term good efficacy of ustekinumab not only on paradoxical forms of psoriasis induced by anti-TNF-α drugs, but also on the articular involvement in a patient affected by RA and in a patient affected by Sjögren syndrome

    Autoantibodies in inflammatory arthritis

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    Rheumatoid arthritis (RA) is a systemic chronic inflammatory disease characterized by extensive synovitis resulting in erosions of articular cartilage and marginal bone with joint destruction. The lack of immunological tolerance in RA represents the first step toward the development of autoimmunity. Susceptible individuals, under the influence of environmental factors, such as tobacco smoke, and silica exposure, develop autoimmune phenomena that result in the presence of autoantibodies. HLA and non-HLA haplotypes play a major role in determining the development of specific autoantibodies differentiating anti-citrullinated antibodies (ACPA)-positive and negative RA patients. Rheumatoid factor (RF) and ACPA are the serological markers for RA, and during the preclinical immunological phase, autoantibody titers increase with a progressive spread of ACPA antigens repertoire. The presence of ACPA represents an independent risk factor for developing RA in patients with undifferentiated arthritis or arthralgia. Moreover, anti-CarP antibodies have been identified in patients with RA as well as in individuals before the onset of clinical symptoms of RA. Several autoantibodies mainly targeting post-translational modified proteins have been investigated as possible biomarkers to improve the early diagnosis, prognosis and response to therapy in RA patients. Psoriatic arthritis (PsA) is distinguished from RA by infrequent positivity for RF and ACPA, together with other distinctive clinical features. Actually, specific autoantibodies have not been described. Recently, anti-CarP antibodies have been reported in sera from PsA patients with active disease. Further investigations on autoantibodies showing high specificity and sensibility as well as relevant correlation with disease severity, progression, and response to therapy are awaited in inflammatory arthritides

    Impeded Growth of Magnetic Flux Bubbles in the Intermediate State Pattern of Type I Superconductors

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    Normal state bubble patterns in Type I superconducting Indium and Lead slabs are studied by the high resolution magneto-optical imaging technique. The size of bubbles is found to be almost independent of the long-range interaction between the normal state domains. Under bubble diameter and slab thickness proper scaling, the results gather onto a single master curve. On this basis, in the framework of the "current-loop" model [R.E. Goldstein, D.P. Jackson and A.T. Dorsey, Phys. Rev. Lett. 76, 3818 (1996)], we calculate the equilibrium diameter of an isolated bubble resulting from the competition between the Biot-and-Savart interaction of the Meissner current encircling the bubble and the superconductor-normal interface energy. A good quantitative agreement with the master curve is found over two decades of the magnetic Bond number. The isolation of each bubble in the superconducting matrix and the existence of a positive interface energy are shown to preclude any continuous size variation of the bubbles after their formation, contrary to the prediction of mean-field models.Comment: \'{e}quipe Nanostructures Quantique
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