8,031 research outputs found

    Comparative electrochemical behavior of Prussian blue analogues as a host electrode for rare earth element recovery

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    In this paper, electrodeposited films belonging to the Prussian Blue Analogues (PBAs) family, namely, nickel-hexacyanoferrate (NiHCF) and copper-hexacyanoferrate (CuHCF), were employed as a host material for rare earth elements (REE), and the reported insertion/release study reveals a recovery capability for such valuable metals. The ion insertion/release was accomplished by adopting an electrochemically-driven process. A reversible intercalation was observed while considering both heavy and ligth rare earth elements. The amount of REEs inserted/released over the process and its kinetic evolution during the process were also studied by a chemometric approach. For CuHCF, it was seen that the intercalation of heavy rare earth elements occurs easily respect to the light ones, suggesting a possible selectivity among these ions

    Vortex length, vortex energy and fractal dimension of superfluid turbulence at very low temperature

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    By assuming a self-similar structure for Kelvin waves along vortex loops with successive smaller scale features, we model the fractal dimension of a superfluid vortex tangle in the zero temperature limit. Our model assumes that at each step the total energy of the vortices is conserved, but the total length can change. We obtain a relation between the fractal dimension and the exponent describing how the vortex energy per unit length changes with the length scale. This relation does not depend on the specific model, and shows that if smaller length scales make a decreasing relative contribution to the energy per unit length of vortex lines, the fractal dimension will be higher than unity. Finally, for the sake of more concrete illustration, we relate the fractal dimension of the tangle to the scaling exponents of amplitude and wavelength of a cascade of Kelvin waves.Comment: 12 pages, 1 figur

    Pentraxin-3 in late-preterm newborns with hypoxic respiratory failure.

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    The aim of this study was: echocardiographical assessment of cardiac alterations in late-preterm newborns with hypoxic respiratory failure (HRF), and, study serum pentraxin-3 (PTX-3) in relation to the severity of respiratory impairment and to some echocardiographic parameters (i.e. ejection fraction (EF), stroke volume (SV) and cardiac output (CO). We enrolled in this study 40 newborn infants whose 22 (group I) with moderate HRF and 18 (group II) with severe HRF. In group I the mean values of EF, SV and CO were significantly higher than in the group II. Our results showed a significant increase of PTX-3 in group II patients at 24h of life when compared to group I. Taking patients all together (n=40), we found a significant (R=-73) reverse correlation between EF and serum values of PTX-3. PTX-3 in our patients with HRF is affected by the severity of the hypoxic insult and correlate with the cardio-vascular impairment

    Turbulent superfluid profiles in a counterflow channel

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    We have developed a two-dimensional model of quantised vortices in helium II moving under the influence of applied normal fluid and superfluid in a counterflow channel. We predict superfluid and vortex-line density profiles which could be experimentally tested using recently developed visualization techniques.Comment: 3 double figures, 9 page

    Evaluation of a pipeline for simulation, reconstruction, and classification in ultrasound-aided diffuse optical tomography of breast tumors

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    SIGNIFICANCE: Diffuse optical tomography is an ill-posed problem. Combination with ultrasound can improve the results of diffuse optical tomography applied to the diagnosis of breast cancer and allow for classification of lesions. AIM: To provide a simulation pipeline for the assessment of reconstruction and classification methods for diffuse optical tomography with concurrent ultrasound information. APPROACH: A set of breast digital phantoms with benign and malignant lesions was simulated building on the software VICTRE. Acoustic and optical properties were assigned to the phantoms for the generation of B-mode images and optical data. A reconstruction algorithm based on a two-region nonlinear fitting and incorporating the ultrasound information was tested. Machine learning classification methods were applied to the reconstructed values to discriminate lesions into benign and malignant after reconstruction. RESULTS: The approach allowed us to generate realistic US and optical data and to test a two-region reconstruction method for a large number of realistic simulations. When information is extracted from ultrasound images, at least 75% of lesions are correctly classified. With ideal two-region separation, the accuracy is higher than 80%. CONCLUSIONS: A pipeline for the generation of realistic ultrasound and diffuse optics data was implemented. Machine learning methods applied to a optical reconstruction with a nonlinear optical model and morphological information permit to discriminate malignant lesions from benign ones

    Enhanced diffuse optical tomographic reconstruction using concurrent ultrasound information

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    Multimodal imaging is an active branch of research as it has the potential to improve common medical imaging techniques. Diffuse optical tomography (DOT) is an example of a low resolution, functional imaging modality that typically has very low resolution due to the ill-posedness of its underlying inverse problem. Combining the functional information of DOT with a high resolution structural imaging modality has been studied widely. In particular, the combination of DOT with ultrasound (US) could serve as a useful tool for clinicians for the formulation of accurate diagnosis of breast lesions. In this paper, we propose a novel method for US-guided DOT reconstruction using a portable time-domain measurement system. B-mode US imaging is used to retrieve morphological information on the probed tissues by means of a semi-automatical segmentation procedure based on active contour fitting. A two-dimensional to three-dimensional extrapolation procedure, based on the concept of distance transform, is then applied to generate a three-dimensional edge-weighting prior for the regularization of DOT. The reconstruction procedure has been tested on experimental data obtained on specifically designed dual-modality silicon phantoms. Results show a substantial quantification improvement upon the application of the implemented technique. This article is part of the theme issue ‘Synergistic tomographic image reconstruction: part 2’

    Immuno-inflammatory and thrombotic/fibrinolytic variables associated with acute ischemic stroke diagnosis.

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    towards diagnosis of acute ischemic stroke. MATERIALS AND METHODS: We enrolled 120 consecutive patients with a diagnosis of acute ischemic stroke and 123 consecutive hospitalized control patients without a diagnosis of acute ischemic stroke. We evaluated plasma levels of IL-1beta, TNF-beta, IL-6 and IL-10, E-selectin, P-selectin, sICAM-1 and sVCAM-1 as markers of immuno-inflammatory activation, vWF plasma levels as a marker of endothelial dysfunction, TPA antigen and PAI-1 plasma levels as a marker of a prothrombotic state. RESULTS: TNF-alpha, PAI-1 and TPA on bivariate logistic regression were highly correlated to stroke diagnosis. Among the other variables maintained in the final model ILbeta, Selectin E, were significantly associated with acute ischemic stroke diagnosis, whereas IL-6, VICAM-1, ICAM-1 and neutrophil percentage showed only a slight or no association with stroke diagnosis. Furthermore, only the continuous values of TNF-alpha, PAI-1 and TPA showed a significant predictive value and likelihood ratio, with an area under the ROC curve of 98.6%, 97.1% and 99.9%, respectively. DISCUSSION: Our findings could suggest the high diagnostic power of these immuno-inflammatory and thrombotic/fibrinolytic variables in patients with acute ischemic stroke. Although our results are encouraging, additional studies are needed to establish the validity of this approac
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