432 research outputs found

    Influence of the Main Filter on QRS-amplitude and Duration in Human Electrocardiogram.

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    Accurate measurement of electrocardiograms (ECG) is critical for effective diagnosis of patient’s cardiac functions. Detailed examination of filters’ effects on ECG accuracy, reproducibility and robustness covering a wide range of available commercial products can provide valuable information on the relationship between quality and effectiveness of filters, and assessments of patients’ cardiac functions. In this study, ECG device with 12 leads and built-in filters used for ECG measurements was assessed on human volunteers. Results showed that with respect to measuring QRS wave duration and R-amplitude variation, there was a 4 % inaccuracy when the main filter was ON and OFF, and R-amplitude variation was most pronounced in the V4 lead. Accordingly, variability of R-amplitude and length of QRS wave can be reduced by the use of appropriate lead, and filter activation during the ECG assessment

    High resolution infrared absorption spectra, crystal field, and relaxation processes in CsCdBr_3:Pr^3+

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    High resolution low-temperature absorption spectra of 0.2% Pr^3+ doped CsCdBr_3 were measured in the spectral region 2000--7000 cm-1. Positions and widths of the crystal field levels within the 3H5, 3H4, 3F2, and 3F3 multiplets of the Pr^3+ main center have been determined. Hyperfine structure of several spectral lines has been found. Crystal field calculations were carried out in the framework of the semiphenomenological exchange charge model (ECM). Parameters of the ECM were determined by fitting to the measured total splittings of the 3H4 and 3H6 multiplets and to the observed in this work hyperfine splittings of the crystal field levels. One- and two-phonon relaxation rates were calculated using the phonon Green's functions of the perfect (CsCdBr_3) and locally perturbed (impurity dimer centers in CsCdBr_3:Pr^3+) crystal lattice. Comparison with the measured linewidths confirmed an essential redistribution of the phonon density of states in CsCdBr_3 crystals doped with rare-earth ions.Comment: 16 pages, 5 tables, 3 figure

    Spontaneous mode non-invasive ventilation fails to treat respiratory failure in a patient with Multi-mincore disease: a case report

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    The increased morbidity and mortality resulting from respiratory failure in patients with neuromuscular disorders and/or kyphoscoliosis can be reversed with non-invasive ventilation. Spontaneous mode bilevel pressure ventilation is preferred to other modes of ventilation, due to relative ease of use, but may not be suitable for all patients. We report a 27-year old woman with Multi-minicore disease whose respiratory failure was refractory to spontaneous mode bilevel pressure ventilation. When we altered settings and provided mandatory inspiratory rise time and respiratory rate, it augmented her respiratory efforts and improved ventilation. Our case report describes the benefit of individualising non-invasive ventilation in the management of respiratory failure due to neuromuscular weakness and kyphoscoliosis

    High-resolution optical spectroscopy investigation of Nd 2BaNiO 5 and Nd 0.1Y 1.9BaNiO 5 and crystal-field parameters for rare-earth linear-chain nickelates

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    High-resolution spectroscopy of Nd 3+ in Nd 2BaNiO 5 and Y 2BaNiO 5:Nd(5%) powder samples is used to study Nd 3+ crystal-field levels and exchange splittings in these quasi-one-dimensional model compounds. We demonstrate that the Nd 3+ ground-state splitting in the magnetically ordered state of Nd 2BaNiO 5 (T N = 47.5 ± 1 K, as found from our spectroscopic data) accounts for the low-temperature magnetic properties and for the 4-meV mode observed earlier in inelastic neutron scattering experiments. Crystal-field analysis is performed. Its results show that the directions of ordered magnetic moments in Nd 2BaNiO 5 are determined by the single-ion anisotropy of Nd 3+. We argue that the crystal-field parameters obtained for Nd-nickelate (in this work) and Er-nickelate (in our earlier work) can be used to predict the energy-level patterns and magnetic orooerties of other rare-earth linear-chain nickelates. ©2005 The American Physical Society

    Primer to Voltage Imaging With ANNINE Dyes and Two-Photon Microscopy

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    ANNINE-6 and ANNINE-6plus are voltage-sensitive dyes that when combined with two-photon microscopy are ideal for recording of neuronal voltages in vivo, in both bulk loaded tissue and the dendrites of single neurons. Here, we describe in detail but for a broad audience the voltage sensing mechanism of fast voltage-sensitive dyes, with a focus on ANNINE dyes, and how voltage imaging can be optimized with one-photon and two-photon excitation. Under optimized imaging conditions the key strengths of ANNINE dyes are their high sensitivity (0.5%/mV), neglectable bleaching and phototoxicity, a linear response to membrane potential, and a temporal resolution which is faster than the optical imaging devices currently used in neurobiology (order of nanoseconds). ANNINE dyes in combination with two-photon microscopy allow depth-resolved voltage imaging in bulk loaded tissue to study average membrane voltage oscillations and sensory responses. Alternatively, if ANNINE-6plus is applied internally, supra and sub threshold voltage changes can be recorded from dendrites of single neurons in awake animals. Interestingly, in our experience ANNINE-6plus labeling is impressively stable in vivo, such that voltage imaging from single Purkinje neuron dendrites can be performed for 2 weeks after a single electroporation of the neuron. Finally, to maximize their potential for neuroscience studies, voltage imaging with ANNINE dyes and two-photon microscopy can be combined with electrophysiological recording, calcium imaging, and/or pharmacology, even in awake animals

    Clear Cell Renal Cell Carcinoma With a Poorly-Differentiated Component: A Novel Variant Causing Potential Diagnostic Difficulty

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    Background: Several variant histologic patterns of clear cell renal cell carcinoma (RCC) are well known, especially those with sarcomatoid and rhabdoid features. However, we have encountered rare cases in which a high-grade adenocarcinoma or urothelial carcinoma-like component would be difficult to appreciate as clear cell RCC. DesignWe retrieved 26 tumors with histologically typical clear cell RCC juxtaposed to a high-grade non-clear cell component.High grade non-clear cell component was defined as non-sarcomatoid, non-rhabdoid areas that would be difficult to assign as renal cell in origin if viewed in isolation. Tumors were studied with immunohistochemistry and fluorescence in situ hybridization (FISH) or sequencing.ResultsMedian percentage of poorly differentiated component: 50%(IQR20-70). All tumors showed abrupt transition from clear cell carcinoma to poorly-differentiated (non-sarcomatoid/non-rhabdoid) areas, which showed micropapillary (7/26; 27%), urothelial-like (10/26; 39%), and adenocarcinoma NOS features (9/26; 35%). 19 tumors had necrosis. Carbonic anhydrase IX (CA-IX) was uniformly positive in well-differentiated component (20/20); poorly differentiated component showed a median positivity of 82.5% (IQR 65-100). Poorly differentiated component was positive for CK7 (5/19; 26%), CK20 (3/12; 25%), AMACR (7/12; 58%), PAX8 (12/15; 80%), and showed intact FH (6/6; 100%). CDX2 was uniformly negative. Chromosome 3p loss or VHL mutation was present in 8/13 (62%), tested with either FISH (n = 9) or sequencing (n = 4). All tested cases were negative for TFE3 (0/11) and TFEB (0/9) rearrangements on FISH. 5/21 (24%) patients were alive with metastatic disease and 5/21 (24%) had died of disease on follow up. One metastasis was composed only of the poorly-differentiated component and was near-negative for CA-IX. Conclusion: Clear cell RCC with a poorly differentiated component resembling adenocarcinoma or urothelial carcinoma is a novel source of morphologic heterogeneity that has not been previously well characterized. Potential pitfalls include decreased or absent CA-IX staining the high-grade component and aberrant positivity for cytokeratin 7 or 20. With the increasing use of renal mass biopsy and biopsies of metastatic sites for targeted therapy, pathologists should be aware of this entity and consider the possibility of clear cell RCC even for morphologically unusual tumors.https://scholarlycommons.henryford.com/merf2019caserpt/1069/thumbnail.jp

    Optical spectroscopy of Yb2Ti2O7 and Y2Ti2O7: Yb3+ and crystal-field parameters in rare-earth titanate pyrochlores

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    Optical absorption spectra of the Yb2Ti2O7 single crystals and luminescence spectra of the Y2Ti 2O7:Yb (1%) polycrystalline samples were registered at temperatures 4.2-300 K. These spectra and earlier published data on magnetic properties of Yb3+ ions and on the temperature dependence of the electric field gradient at Yb nuclei in Yb2Ti2O 7 were used to analyze the crystal-field parameters in rare-earth titanates with the pyrochlore structure. The self-consistent sets of crystal-field parameters for rare-earth ions in the 16d sites with the D 3d symmetry that describe satisfactory all known single-ion magnetic properties and low-energy excitations in R2Ti2O 7 crystals (R=Tb, Ho, Er, Tm, Yb) are presented

    Stark structure of the Yb3+ ion levels in (YbxY 1-x)2Ti2O7 and the crystal field in rare-earth titanates with a pyrochlore structure

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    The absorption spectra of Yb2Ti2O7 single crystals and the luminescence and luminescence excitation spectra of Y 2Ti2O7: Yb (1%) polycrystals were studied in the temperature range 4.2-300 K. The spectra were analyzed in terms of the crystal-field theory and the exchange-charge model. Based on the set of crystal-field parameters found for Yb2Ti2O7, analogous sets of parameters were determined for other rare-earth titanates and proved to be in reasonable agreement with all available experimental data. © 2005 Pleiades Publishing, Inc

    Developing a model of care for people with end stage chronic obstructive pulmonary disease (COPD) and their carers : Report on NHMRC funded study 519359

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    Extent: 159 p. This report was prepared by A/Prof G Crawford, Ms M Brown, Ms T Burgess, Dr M Brooksbank, A/Prof A Crockett and Ms M Young.This project demonstrated that the needs of people with COPD are not being met. Care for people with advanced COPD has been focused in the acute care setting, with some community support but this has been shown to be inadequate in meeting the day to day and palliative care needs of people with COPD. Application of the chronic disease management model to include people with COPD, with a new level of integration of a palliative approach at all phases of the illness, should be reflected in health policy.Crawford GB, Brown M, Crockett AJ, Burgess TA, Brooksbank MA, Young M, Kralik D, Antic R, Taylor J & Hancock K
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