3,087 research outputs found

    Single-pixel phase-corrected fiber bundle endomicroscopy with lensless focussing capability.

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    In this paper a novel single-pixel method for coherent imaging through an endoscopic fiber bundle is presented. The use of a single-pixel detector allows greater sensitivity over a wider range of wavelengths, which could have significant applications in endoscopic fluorescence microscopy. First, the principle of lensless focussing at the distal end of a coherent fiber bundle is simulated to examine the impact of pixelation at microscopic scales. Next, an experimental optical correlator system using spatial light modulators (SLMs) is presented. A simple contrast imaging method of characterizing and compensating phase aberrations introduced by fiber bundles is described. Experimental results are then presented showing that our phase compensation method enables characterization of the optical phase profile of individual fiberlets. After applying this correction, early results demonstrating the ability of the system to electronically adjust the focal plane at the distal end of the fiber bundle are presented. The structural similarity index (SSIM) between the simulated image and the experimental focus-adjusted image increases noticeably when the phase correction is applied and the retrieved image is visually recognizable. Strategies to improve image quality are discussed.G. Gordon would like to acknowledge support from a Henslow Research Fellowship from the Cambridge Philosophical Society, as well as research funding from the Cambridge Cancer Centre and Cancer Research UK. S. Bohndiek would like to acknowledge research funding from a Cancer Research UK Career Establishment Award and the CRUK-EPSRC Cancer Imaging Centre in Cambridge and Manchester.This is the final version of the article. It first appeared from IEEE via http://dx.doi.org/10.1109/JLT.2015.243681

    The impact of multiple sclerosis on the identity of mothers in Italy

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    Purpose: This paper reports on one of the themes that emerged from the analysis of the study, regarding the perceived influence of multiple sclerosis (MS) on the identity of mothers in the socio-cultural context of Italy. Method: In-depth interviews were conducted with 16 women at various stages of MS, with follow up interviews with seven of the women. Phenomenology guided the methodology and the analysis was conducted using interpretative phenomenological analysis. Results: Through the research the value of motherhood to the women who participated emerged. The findings illustrated how many strove to maintain controlof their MS, which led to some making comparisons of themselves and other mothers and feeling different. Some women described how they adjusted their roles and found strength in being mothers but others spoke of their feelings of loss. Most women described living in the moment, appreciating the present and living each day as it came. Another significant experience was fear of stigma, both realized in the form of “pity” from others, and the perceived and actual associated stigma for their families. This contributed to why some women were reluctant to disclose their condition. The mothers who took part in this study differed in how they perceived their disabled identity. Conclusion: Although this study was conducted in the socio-cultural setting of Italy, the findings have implications for professionals working with disabled mothers and women with MS in Italy and beyond; including recognizing the value associated with fully identifying oneself as a mother, rather than solely focusing on doingmothering tasks. • Implications for Rehabilitation • Professionals need to be mindful of the value of motherhood for women with multiple sclerosis. • Professionals should support women who feel like they are battling with maintaining control of their multiple sclerosis, who may be adjusting their identity as mothers; recognizing that they may be influenced by the stage of their multiple sclerosis and whether they were diagnosed before or after having their children. • Women can have feelings of loss related to their ability to fully participate in their children’s lives and professionals should work with women to help them identify the value of their mothering role not only in physically participating in activities but also in being emotionally and physically present as a mother

    Full-field quantitative phase and polarisation-resolved imaging through an optical fibre bundle.

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    Flexible optical fibres, used in conventional medical endoscopy and industrial inspection, scramble phase and polarisation information, restricting users to amplitude-only imaging. Here, we exploit the near-diagonality of the multi-core fibre (MCF) transmission matrix in a parallelised fibre characterisation architecture, enabling accurate imaging of quantitative phase (error <0.3 rad) and polarisation-resolved (errors <10%) properties. We first demonstrate accurate recovery of optical amplitude and phase in two polarisations through the MCF by measuring and inverting the transmission matrix, and then present a robust Bayesian inference approach to resolving 5 polarimetric properties of samples. Our method produces high-resolution (9.0±2.6μm amplitude, phase; 36.0±10.4μm polarimetric) full-field images at working distances up to 1mm over a field-of-view up to 750×750μm 2 using an MCF with potential for flexible operation. We demonstrate the potential of using quantitative phase for computational image focusing and polarisation-resolved properties in imaging birefringence

    Assessing Susceptibility from Early-Life Exposure to Carcinogens

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    Cancer risk assessment methods currently assume that children and adults are equally susceptible to exposure to chemicals. We reviewed available scientific literature to determine whether this was scientifically supported. We identified more than 50 chemicals causing cancer after perinatal exposure. Human data are extremely limited, with radiation exposures showing increased early susceptibility at some tumor sites. Twenty-seven rodent studies for 18 chemicals had sufficient data after postnatal and adult exposures to quantitatively estimate potential increased susceptibility from early-life exposure, calculated as the ratio of juvenile to adult cancer potencies for three study types: acute dosing, repeated dosing, and lifetime dosing. Twelve of the chemicals act through a mutagenic mode of action. For these, the geometric mean ratio was 11 for lifetime exposures and 8.7 for repeat exposures, with a ratio of 10 for these studies combined. The geometric mean ratio for acute studies is 1.5, which was influenced by tissue-specific results [geometric mean ratios for kidney, leukemia, liver, lymph, mammary, nerve, reticular tissue, thymic lymphoma, and uterus/vagina > 1 (range, 1.6–8.1); forestomach, harderian gland, ovaries, and thyroid < 1 (range, 0.033–0.45)]. Chemicals causing cancer through other modes of action indicate some increased susceptibility from postnatal exposure (geometric mean ratio is 3.4 for lifetime exposure, 2.2 for repeat exposure). Early exposures to compounds with endocrine activity sometimes produce different tumors after exposures at different ages. These analyses suggest increased susceptibility to cancer from early-life exposure, particularly for chemicals acting through a mutagenic mode of action

    A review of clinical decision-making: Models and current research

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    Aims and objectives: The aim of this paper was to review the current literature with respect to clinical decision-making models and the educational application of models to clinical practice. This was achieved by exploring the function and related research of the three available models of clinical decision making: information processing model, the intuitive-humanist model and the clinical decision making model. Background: Clinical decision-making is a unique process that involves the interplay between knowledge of pre-existing pathological conditions, explicit patient information, nursing care and experiential learning. Historically, two models of clinical decision making are recognised from the literature; the information processing model and the intuitive-humanist model. The usefulness and application of both models has been examined in relation the provision of nursing care and care related outcomes. More recently a third model of clinical decision making has been proposed. This new multidimensional model contains elements of the information processing model but also examines patient specific elements that are necessary for cue and pattern recognition. Design: Literature review Methods: Evaluation of the literature generated from MEDLINE, CINAHL, OVID, PUBMED and EBESCO systems and the Internet from 1980 – November 2005

    A clinically translatable hyperspectral endoscopy (HySE) system for imaging the gastrointestinal tract.

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    Hyperspectral imaging (HSI) enables visualisation of morphological and biochemical information, which could improve disease diagnostic accuracy. Unfortunately, the wide range of image distortions that arise during flexible endoscopy in the clinic have made integration of HSI challenging. To address this challenge, we demonstrate a hyperspectral endoscope (HySE) that simultaneously records intrinsically co-registered hyperspectral and standard-of-care white light images, which allows image distortions to be compensated computationally and an accurate hyperspectral data cube to be reconstructed as the endoscope moves in the lumen. Evaluation of HySE performance shows excellent spatial, spectral and temporal resolution and high colour fidelity. Application of HySE enables: quantification of blood oxygenation levels in tissue mimicking phantoms; differentiation of spectral profiles from normal and pathological ex vivo human tissues; and recording of hyperspectral data under freehand motion within an intact ex vivo pig oesophagus model. HySE therefore shows potential for enabling HSI in clinical endoscopy

    Quality Control of Motor Unit Number Index (MUNIX) Measurements in 6 Muscles in a Single-Subject “Round-Robin” Setup

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    Background Motor Unit Number Index (MUNIX) is a neurophysiological measure that provides an index of the number of lower motor neurons in a muscle. Its performance across centres in healthy subjects and patients with Amyotrophic Lateral Sclerosis (ALS) has been established, but inter-rater variability between multiple raters in one single subject has not been investigated. Objective To assess reliability in a set of 6 muscles in a single subject among 12 examiners (6 experienced with MUNIX, 6 less experienced) and to determine variables associated with variability of measurements. Methods Twelve raters applied MUNIX in six different muscles (abductor pollicis brevis (APB), abductor digiti minimi (ADM), biceps brachii (BB), tibialis anterior (TA), extensor dig. brevis (EDB), abductor hallucis (AH)) twice in one single volunteer on consecutive days. All raters visited at least one training course prior to measurements. Intra- and inter-rater variability as determined by the coefficient of variation (COV) between different raters and their levels of experience with MUNIX were compared. Results Mean intra-rater COV of MUNIX was 14.0% (Âą6.4) ranging from 5.8 (APB) to 30.3% (EDB). Mean inter-rater COV was 18.1 (Âą5.4) ranging from 8.0 (BB) to 31.7 (AH). No significant differences of variability between experienced and less experienced raters were detected. Conclusion We provide evidence that quality control for neurophysiological methods can be performed with similar standards as in laboratory medicine. Intra- and inter-rater variability of MUNIX is muscle-dependent and mainly below 20%. Experienced neurophysiologists can easily adopt MUNIX and adequate teaching ensures reliable utilization of this method
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