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Monika Špinarová, Jaroslav Meluzín, Helena Podroužková, Radka Štěpánová, Lenka Špinarová
Heart failure with preserved ejection fraction (HFpEF) is a serious clinical disease. The pathophysiology of HFpEF is complex, and specific diagnostic criteria have evolved over time. Limited data are available on the quantification of diastolic function using two-dimensional real-time echocardiography, and a simple parameter has not yet been established. The aim of this work is to evaluate new echocardiographic parameters-the diastolic wall strain of the posterior wall (DWS PW) and the vortex formation time (VFT)...
August 17, 2017: International Journal of Cardiovascular Imaging
Soojung Claire Hur, James Che, Dino Di Carlo
Circulating tumor cells (CTCs) are disseminated tumor cells that reflect the tumors of origin and can provide a liquid biopsy that would potentially enable noninvasive tumor profiling, treatment monitoring, and identification of targeted treatments. Accurate and rapid purification of CTCs holds great potential to improve cancer care but the task remains technically challenging. Microfluidic isolation of CTCs within microscale vortices enables high-throughput and size-based purification of rare CTCs from bodily fluids...
2017: Methods in Molecular Biology
D Karpov, Z Liu, T Dos Santos Rolo, R Harder, P V Balachandran, D Xue, T Lookman, E Fohtung
Topological defects of spontaneous polarization are extensively studied as templates for unique physical phenomena and in the design of reconfigurable electronic devices. Experimental investigations of the complex topologies of polarization have been limited to surface phenomena, which has restricted the probing of the dynamic volumetric domain morphology in operando. Here, we utilize Bragg coherent diffractive imaging of a single BaTiO3 nanoparticle in a composite polymer/ferroelectric capacitor to study the behavior of a three-dimensional vortex formed due to competing interactions involving ferroelectric domains...
August 17, 2017: Nature Communications
Cheng-Wei Qiu, Yuanjie Yang
No abstract text is available yet for this article.
August 18, 2017: Science
Morteza Salehi, S A Jafari
We suggest that spin-singlet pseudo-scalar s-wave superconducting pairing creates a two dimensional sea of Majorana fermions on the surface of three dimensional Dirac superconductors (3DDS). This pseudo-scalar superconducting order parameter Δ5, in competition with scalar Dirac mass m, leads to a topological phase transition due to band inversion. We find that a perfect Andreev-Klein reflection is guaranteed by presence of anomalous Andreev reflection along with the conventional one. This effect manifests itself in a resonant peak of the differential conductance...
August 15, 2017: Scientific Reports
Dan Zhang, Xing Liu, Lingmeng Yang, Xinghua Li, Zhaoyang Zhang, Yanpeng Zhang
We have experimentally generated a vortex six-wave mixing (SWM) signal via a photonic band gap structure in a hot atomic ensemble. The output SWM carrying orbital angular momentum, transferred from a probe beam, has the interaction with the nonlinear effect in the multilevel atomic system. Our results show that a spatial SWM image can be modulated by the detunings and intensities of the related generating fields. Also, the nonreciprocal feature of the SWM signal is demonstrated. Such characteristics can potentially be used in information processing...
August 15, 2017: Optics Letters
Jingfu Ye, Yan Li, Yanhua Han, Duo Deng, Xiaoya Su, He Song, Jianmin Gao, Shiliang Qu
A mode convertor was proposed and investigated for generating vortex modes in a ring-core fiber based on a plasmonic q-plate (PQP), which is composed of specially organized L-shaped resonator (LSR) arrays. A multicore fiber was used to transmit fundamental modes, and the LSR arrays were used to modulate phases of these fundamental modes. Behind the PQP, the transmitted fundamental modes with gradient phase distribution can be considered as the incident lights for generating broadband vortex modes in the ring-core fiber filter...
August 15, 2017: Optics Letters
Qianbin Zhao, Sheng Yan, Dan Yuan, Jun Zhang, Haiping Du, Gursel Alici, Weihua Li
In this paper, we proposed a microparticle manipulation approach, by which particles are able to be guided to different equilibrium positions through modulating the Reynolds number. In the microchannel with arc-shaped groove arrays, secondary flow vortex arisen due to the pressure gradient varies in the aspects of both magnitude and shape with the increase of Reynolds number. And the variation of secondary flow vortex brings about different focusing modes of microparticles in the microchannel. We investigated the focusing phenomenon experimentally and analyzed the mechanism through numerical simulations...
August 14, 2017: IEEE Transactions on Biomedical Circuits and Systems
Anna M Donnell, Stephanie Lewis, Sami Abraham, Kavitha Subramanian, Julio Landero Figueroa, George S Deepe, Anne P Vonderheide
This work sought to assess optimal extraction conditions in the study of the metalloproteome of the dimorphic fungus Histoplasma capsulatum. One of the body's responses to H. capsulatum infection is sequestration of zinc within host macrophage (MØ), as reported by Vignesh et al. (Immunity 39:697-710, 2013) and Vignesh et al. (PLOS Pathog 9:E1003815, 2013). Thus, metalloproteins containing zinc were of greatest interest as it plays a critical role in survival of the fungus. One challenge in metalloproteomics is the preservation of the native structure of proteins to retain non-covalently bound metals...
August 12, 2017: Analytical and Bioanalytical Chemistry
Kondo Claude Assi, Etienne Gay, Christophe Chnafa, Simon Mendez, Franck Nicoud, Juan F P J Abascal, Pierre Lantelme, François Tournoux, Damien Garcia
We propose a regularized least-squares method for reconstructing 2D velocity vector fields within the left ventricular cavity from single-view color Doppler echocardiographic images. Vector flow mapping is formulated as a quadratic optimization problem based on an [Formula: see text]-norm minimization of a cost function composed of a Doppler data-fidelity term and a regularizer. The latter contains three physically interpretable expressions related to 2D mass conservation, Dirichlet boundary conditions, and smoothness...
August 11, 2017: Physics in Medicine and Biology
Marie de Saint Victor, Dario Carugo, Lester C Barnsley, Joshua Owen, Constantin C Coussios, Eleanor Stride
Ultrasound and microbubbles have been shown to accelerate the breakdown of blood clots both in vitro and in vivo. Clinical translation of this technology is still limited, however, in part by inefficient microbubble delivery to the thrombus. This study examines the obstacles to delivery posed by fluid dynamic conditions in occluded vasculature and investigates whether magnetic targeting can improve microbubble delivery. A two-dimensional computational fluid dynamic (CFD) model of a fully occluded Y-shaped microarterial bifurcation was developed to determine: (i) the fluid dynamic field in the vessel with inlet velocities from 1-100mm/s (corresponding to Reynolds numbers 0...
August 10, 2017: Physics in Medicine and Biology
R P Beardsley, S Bowe, D E Parkes, C Reardon, K W Edmonds, B L Gallagher, S A Cavill, A W Rushforth
Concepts for information storage and logical processing based on magnetic domain walls have great potential for implementation in future information and communications technologies. To date, the need to apply power hungry magnetic fields or heat dissipating spin polarized currents to manipulate magnetic domain walls has limited the development of such technologies. The possibility of controlling magnetic domain walls using voltages offers an energy efficient route to overcome these limitations. Here we show that a voltage-induced uniaxial strain induces reversible deterministic switching of the chirality of a magnetic vortex wall...
August 8, 2017: Scientific Reports
Xiaoming Chen, Yukun Ren, Weiyu Liu, Xiangsong Feng, Yankai Jia, Ye Tao, Hongyuan Jiang
Continuous dielectrophoretic separation is recognized as a powerful technique for a large number of applications including early-stage cancer diagnosis, water quality analysis, and stem cell-based therapy. Generally, the prefocusing of a particle mixture into a stream is an essential process to ensure all particles are subjected to the same electric field geometry in the separation region. However, accomplishing this focusing process either requires hydrodynamic squeezing, which requires an encumbering peripheral system and a complicated operation to drive and control the fluid motion, or depends on dielectro-phoretic forces, which are highly sensitive to the dielectric characterization of particles...
August 7, 2017: Analytical Chemistry
A R Damodaran, J D Clarkson, Z Hong, H Liu, A K Yadav, C T Nelson, S-L Hsu, M R McCarter, K-D Park, V Kravtsov, A Farhan, Y Dong, Z Cai, H Zhou, P Aguado-Puente, P García-Fernández, J Íñiguez, J Junquera, A Scholl, M B Raschke, L-Q Chen, D D Fong, R Ramesh, L W Martin
Systems that exhibit phase competition, order parameter coexistence, and emergent order parameter topologies constitute a major part of modern condensed-matter physics. Here, by applying a range of characterization techniques, and simulations, we observe that in PbTiO3/SrTiO3 superlattices all of these effects can be found. By exploring superlattice period-, temperature- and field-dependent evolution of these structures, we observe several new features. First, it is possible to engineer phase coexistence mediated by a first-order phase transition between an emergent, low-temperature vortex phase with electric toroidal order and a high-temperature ferroelectric a1/a2 phase...
August 7, 2017: Nature Materials
Chang Xu, Yiyi Liao, Chunyan Fang, Makoto Tsunoda, Yingxia Zhang, Yanting Song, Shiming Deng
In this paper, a novel method of QuEChERS-based extraction coupled with high-performance liquid chromatography has been developed for the simultaneous determination of ursolic acid (UA) and oleanolic acid (OA) in guava leaves. The QuEChERS-based extraction parameters, including the amount of added salt, vortex-assisted extraction time, and absorbent amount, and the chromatographic conditions were investigated for the analysis of UA and OA in guava leaves. Under the optimized conditions, the method showed good linearity over a range of 1-320 μg mL(-1), with correlation coefficients above 0...
2017: Journal of Analytical Methods in Chemistry
Koen van Kruining, Armen G Hayrapetyan, Jörg B Götte
We present a relativistic description of electron vortex beams in a homogeneous magnetic field. Including spin from the beginning reveals that spin-polarized electron vortex beams have a complicated azimuthal current structure, containing small rings of counterrotating current between rings of stronger corotating current. Contrary to many other problems in relativistic quantum mechanics, there exists a set of vortex beams with exactly zero spin-orbit mixing in the highly relativistic and nonparaxial regime...
July 21, 2017: Physical Review Letters
Thomas Le Reun, Benjamin Favier, Adrian J Barker, Michael Le Bars
The combination of elliptical deformation of streamlines and vorticity can lead to the destabilization of any rotating flow via the elliptical instability. Such a mechanism has been invoked as a possible source of turbulence in planetary cores subject to tidal deformations. The saturation of the elliptical instability has been shown to generate turbulence composed of nonlinearly interacting waves and strong columnar vortices with varying respective amplitudes, depending on the control parameters and geometry...
July 21, 2017: Physical Review Letters
Giovanni Magno, Mickael Fevrier, Philippe Gogol, Abdelhanin Aassime, Alexandre Bondi, Robert Mégy, Béatrice Dagens
A strong coupling regime is demonstrated at near infrared between metallic nanoparticle chains (MNP), supporting localized surface plasmons (LSP), and dielectric waveguides (DWGs) having different core materials. MNP chains are deposited on the top of these waveguides in such a way that the two guiding structures are in direct contact with each other. The strong coupling regime implies (i) a strong interpenetration of the bare modes forming two distinct supermodes and (ii) a large power overlap up to the impossibility to distinguish the power quota inside each bare structure...
August 3, 2017: Scientific Reports
Martin W Scheeler, Wim M van Rees, Hridesh Kedia, Dustin Kleckner, William T M Irvine
Helicity, a topological measure of the intertwining of vortices in a fluid flow, is a conserved quantity in inviscid fluids but can be dissipated by viscosity in real flows. Despite its relevance across a range of flows, helicity in real fluids remains poorly understood because the entire quantity is challenging to measure. We measured the total helicity of thin-core vortex tubes in water. For helical vortices that are stretched or compressed by a second vortex, we found conservation of total helicity. For an isolated helical vortex, we observed evolution toward and maintenance of a constant helicity state after the dissipation of twist helicity by viscosity...
August 4, 2017: Science
Z Y Hong, J F Yin, W Zhai, N Yan, W L Wang, J Zhang, Bruce W Drinkwater
Acoustic levitation in gaseous media provides a tool to process solid and liquid materials without the presence of surfaces such as container walls and hence has been used widely in chemical analysis, high-temperature processing, drop dynamics and bioreactors. To date high-density objects can only be acoustically levitated in simple standing-wave fields. Here we demonstrate the ability of a small number of peripherally placed sources to generate acoustic vortex fields and stably levitate a wide range of liquid and solid objects...
August 2, 2017: Scientific Reports
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