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Kardiologiia Jul 2017Analysis of diagnostic and prognostic possibilities of echocardiography in patients with Takotsubo syndrome is given in this review. Special characteristics of local... (Review)
Review
Analysis of diagnostic and prognostic possibilities of echocardiography in patients with Takotsubo syndrome is given in this review. Special characteristics of local wall motion abnormalities of the left ventricle are presented and main variants of transitory derangements of local contractility are described. Changes of parameters of deformation of left and right ventricles in acute period and during follow-up are analyzed in detail. A spectrum of complications of the syndrome in detection of which echocardiography plays the leading role is outlined. The review also contains analysis of prognostically unfavorable states and echocardiographic parameters specific for Takotsubo syndrome.
Topics: Echocardiography; Heart Ventricles; Humans; Prognosis; Takotsubo Cardiomyopathy
PubMed: 29041884
DOI: 10.18087/cardio.2017.7.10009 -
Physical Review Letters Jul 2017Using the sensitivity of optical second harmonic generation to currents, we demonstrate the generation of 250-fs long spin current pulses in Fe/Au/Fe/MgO(001) spin...
Using the sensitivity of optical second harmonic generation to currents, we demonstrate the generation of 250-fs long spin current pulses in Fe/Au/Fe/MgO(001) spin valves. The temporal profile of these pulses indicates ballistic transport of hot electrons across a sub-100 nm Au layer. The pulse duration is primarily determined by the thermalization time of laser-excited hot carriers in Fe. Considering the calculated spin-dependent Fe/Au interface transmittance we conclude that a nonthermal spin-dependent Seebeck effect is responsible for the generation of ultrashort spin current pulses. The demonstrated rotation of spin polarization of hot electrons upon interaction with noncollinear magnetization at Au/Fe interfaces holds high potential for future spintronic devices.
PubMed: 28731774
DOI: 10.1103/PhysRevLett.119.017202 -
Nanoscale interface confinement of ultrafast spin transfer torque driving non-uniform spin dynamics.Nature Communications Apr 2017Spintronics had a widespread impact over the past decades due to transferring information by spin rather than electric currents. Its further development requires...
Spintronics had a widespread impact over the past decades due to transferring information by spin rather than electric currents. Its further development requires miniaturization and reduction of characteristic timescales of spin dynamics combining the sub-nanometre spatial and femtosecond temporal ranges. These demands shift the focus of interest towards the fundamental open question of the interaction of femtosecond spin current (SC) pulses with a ferromagnet (FM). The spatio-temporal properties of the impulsive spin transfer torque exerted by ultrashort SC pulses on the FM open the time domain for probing non-uniform magnetization dynamics. Here we employ laser-generated ultrashort SC pulses for driving ultrafast spin dynamics in FM and analysing its transient local source. Transverse spins injected into FM excite inhomogeneous high-frequency spin dynamics up to 0.6 THz, indicating that the perturbation of the FM magnetization is confined to 2 nm.
PubMed: 28406144
DOI: 10.1038/ncomms15007 -
Journal of Physics. Condensed Matter :... May 2017We discuss fundamental aspects of laser-induced ultrafast demagnetization probed by the time-resolved magneto-optical Kerr effect (MOKE). Studying thin Fe films on MgO...
We discuss fundamental aspects of laser-induced ultrafast demagnetization probed by the time-resolved magneto-optical Kerr effect (MOKE). Studying thin Fe films on MgO substrate in the absence of electronic transport, we demonstrate how to disentangle pump-induced variations of magnetization and magneto-optical coefficients. We provide a mathematical formalism for retrieving genuine laser-induced magnetization dynamics and discuss its applicability in real experimental situations. We further stress the importance of temporal resolution achieved in the experiments and argue that measurements of both time-resolved MOKE rotation and ellipticity are needed for the correct assessment of magnetization dynamics on sub-picosecond timescales. The framework developed here sheds light onto the details of the time-resolved MOKE technique and contributes to the understanding of the interplay between ultrafast laser-induced optical and magnetic effects.
PubMed: 28349899
DOI: 10.1088/1361-648X/aa63c6 -
Kardiologiia Feb 2016The review is devoted to merits and demerits of a new method of assessment of condition of the heart - speckle-tracking echocardiography. Speckle-tracking... (Review)
Review
The review is devoted to merits and demerits of a new method of assessment of condition of the heart - speckle-tracking echocardiography. Speckle-tracking echocardiography is a perspective method allowing to register disorders of both global and regional contractile motion.
Topics: Echocardiography; Humans; Myocardial Ischemia
PubMed: 28294755
DOI: 10.18565/cardio.2016.2.79-84 -
Kardiologiia Jan 2017This literature review is devoted to noninvasive evaluation of the left ventricular (LV) diastolic function by echocardiography with special stress on existing problems...
This literature review is devoted to noninvasive evaluation of the left ventricular (LV) diastolic function by echocardiography with special stress on existing problems of detection of LV dysfunction by Doppler echocardiography of transmitral blood flow. Basing on existent algorithms one often cannot clearly judge whether LV dysfunction is present even when such methods are used as assessment of blood flow in pulmonary veins, transmitral blood flow during the Valsalva maneuver, etc. The review also contains discussion and analysis of newly suggested Doppler echocardiography based algorithms of detection of LV diastolic dysfunction and estimation of its severity (two-dimensional deformation of left atrial walls, three-dimensional echocardiography and three-dimensional deformation of the left ventricle).
Topics: Diastole; Echocardiography, Doppler; Humans; Ventricular Dysfunction, Left; Ventricular Function, Left
PubMed: 28290836
DOI: No ID Found -
Kardiologiia Feb 2017to compare non-invasive evaluation of left ventricular (LV) diastolic function (DF) by echocardiography using algorithms of the 2009 and 2016 American Society of...
OBJECTIVE
to compare non-invasive evaluation of left ventricular (LV) diastolic function (DF) by echocardiography using algorithms of the 2009 and 2016 American Society of Echocardiography (ASE)/European Association of Echocardiography (EAE, now European Association of Cardiovascular Imaging [EACVI]) Recommendations.
MATERIAL AND METHODS
The study included 100 patients with sinus rhythm and preserved left ventricular (LV) ejection fraction (EF). In all patients LV DF was assessed using both algorithms. In accordance with the ASE/EAE 2009 algorithm pulsed-wave tissue Doppler early diastolic velocity (e velocity) at lateral and septal basal regions of mitral annulus, as well as left atrial maximum volume index were evaluated. In accordance with the ASE/EACVI 2016 algorithm for judging the presence of LV diastolic dysfunction (DD), in addition to the two above-described criteria, E/e ratio and peak velocity of tricuspid regurgitation were analyzed. In the presence of 1 and more or equal 3 criteria LVDF was classified as normal and DD, respectively. If 2 criteria were detected result was considered as indeterminate.
RESULTS
In 70% of patients in accordance with the ASE/EACVI 2016 algorithm DF was evaluated with 4 and in 100% - with 3 proposed criteria. The reason for using only 3 criteria was inadequate imaging of tricuspid regurgitation flow by continuous wave Doppler. Use of ASE/EACVI 2016 compared with the ASE/EAE 2009 algorithm in patients with normal LV EF led to a significant decrease of the number of patients with LV DD (13 vs. 27%, respectively; <0.05). The main reason for this redistribution was lowering of the cutoff value of annular e septal velocity from 8 (2009 algorithm) to 7 cm/sec (2016 algorithm). Frequency of indeterminate results with the use of 2016 algorithm was 2 times less than with the use of 2009 algorithm (15 vs. 36%, respectively; p<0.001).
CONCLUSION
In patients with preserved LVEF the use of ASE/EACVI 2016 algorithm led to redistribution of data of evaluation of LVDF by echocardiography towards reduction of the number of patients with LV DD and with indeterminate results.
Topics: Algorithms; Diastole; Echocardiography; Humans; Mitral Valve; Stroke Volume; Ventricular Dysfunction, Left; Ventricular Function, Left
PubMed: 28290789
DOI: No ID Found -
Optics Express Jan 2017Scintillator-based X-ray imaging is a powerful technique for noninvasive real-space microscopic structural investigation such as synchrotron-based computed tomography....
Scintillator-based X-ray imaging is a powerful technique for noninvasive real-space microscopic structural investigation such as synchrotron-based computed tomography. The resolution of an optical image formed by scintillation emission is fundamentally diffraction limited. To overcome this limit, stimulated scintillation emission depletion (SSED) X-ray imaging, based on stimulated emission depletion (STED) microscopy, has been recently developed. This technique imposes new requirements on the scintillator material: efficient de-excitation by the STED-laser and negligible STED-laser excited luminescence. In this work, luminescence depletion was measured in several commonly-used Ce, Tb, and Eu - doped scintillators using various STED lasers. The depletion of Tb and Eu via 4f-4f transitions was more efficient (P = 8…19 mW) than Ce depletion via 5d-4f transitions (P = 43…45 mW). Main origins of STED-laser excited luminescence were one- and two-photon excitation, and scintillator impurities. LSO:Tb scintillator and a 628 nm cw STED-laser is the most promising combination for SSED satisfying the above-mentioned requirements.
PubMed: 28158009
DOI: 10.1364/OE.25.001251 -
Optics Express Jan 2017X-ray microtomography is a widely applied tool for noninvasive structure investigations. The related detectors are usually based on a scintillator screen for the fast in...
X-ray microtomography is a widely applied tool for noninvasive structure investigations. The related detectors are usually based on a scintillator screen for the fast in situ conversion of an X-ray image into an optical image. Spatial resolution of the latter is fundamentally diffraction limited. In this work, we introduce stimulated scintillation emission depletion (SSED) X-ray imaging where, similar to stimulated emission depletion (STED) microscopy, a depletion beam is applied to the scintillator screen to overcome the diffraction limit. The requirements for the X-ray source, the X-ray flux, the scintillator screen, and the STED beam were evaluated. Fundamental spatial resolution limits due to the spread of absorbed X-ray energy were estimated with Monte Carlo simulations. The SSED proof-of-concept experiments demonstrated 1) depletion of X-ray excited scintillation, 2) partial confinement of scintillating regions to sub-diffraction sized volumes, and 3) improvement of the imaging contrast by applying SSED.
PubMed: 28157955
DOI: 10.1364/OE.25.000654 -
Reports on Progress in Physics.... Dec 2016This paper describes the physics case for a new fixed target facility at CERN SPS. The SHiP (search for hidden particles) experiment is intended to hunt for new physics...
This paper describes the physics case for a new fixed target facility at CERN SPS. The SHiP (search for hidden particles) experiment is intended to hunt for new physics in the largely unexplored domain of very weakly interacting particles with masses below the Fermi scale, inaccessible to the LHC experiments, and to study tau neutrino physics. The same proton beam setup can be used later to look for decays of tau-leptons with lepton flavour number non-conservation, [Formula: see text] and to search for weakly-interacting sub-GeV dark matter candidates. We discuss the evidence for physics beyond the standard model and describe interactions between new particles and four different portals-scalars, vectors, fermions or axion-like particles. We discuss motivations for different models, manifesting themselves via these interactions, and how they can be probed with the SHiP experiment and present several case studies. The prospects to search for relatively light SUSY and composite particles at SHiP are also discussed. We demonstrate that the SHiP experiment has a unique potential to discover new physics and can directly probe a number of solutions of beyond the standard model puzzles, such as neutrino masses, baryon asymmetry of the Universe, dark matter, and inflation.
PubMed: 27775925
DOI: 10.1088/0034-4885/79/12/124201