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https://www.readbyqxmd.com/read/28729642/imaging-of-super-fast-dynamics-and-flow-instabilities-of-superconducting-vortices
#1
L Embon, Y Anahory, Ž L Jelić, E O Lachman, Y Myasoedov, M E Huber, G P Mikitik, A V Silhanek, M V Milošević, A Gurevich, E Zeldov
Quantized magnetic vortices driven by electric current determine key electromagnetic properties of superconductors. While the dynamic behavior of slow vortices has been thoroughly investigated, the physics of ultrafast vortices under strong currents remains largely unexplored. Here, we use a nanoscale scanning superconducting quantum interference device to image vortices penetrating into a superconducting Pb film at rates of tens of GHz and moving with velocities of up to tens of km/s, which are not only much larger than the speed of sound but also exceed the pair-breaking speed limit of superconducting condensate...
July 20, 2017: Nature Communications
https://www.readbyqxmd.com/read/28726408/a-computational-study-on-the-addition-of-hono-to-alkynes-towards-the-synthesis-of-isoxazoles-a-bifurcation-pseudopericyclic-pathways-and-a-barrierless-reaction-on-the-potential-energy-surface
#2
Ang Zuo, David Martin Birney
Homopropargyl alcohols react with t-BuONO to form acyloximes which can be oxidatively cyclized to yield isoxazoles. The mechanism for the initial reaction of HONO with alkynes to form acyloximes (e.g. 13c) has been explored at the B3LYP/6-31G(d,p) + ZPVE level of theory. The observed chemoselectivity and regioselectivity are explained via an acid-catalyzed mechanism. Furthermore, the potential energy surface revealed numerous surprising features. The addition of HONO (8) to protonated 1-phenylpropyne (18) is calculated to follow a reaction pathway involving sequential transition states (TS6 and TS8), for which reaction dynamics likely play a role...
July 20, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28726204/association-of-level-of-proprotein-convertase-subtilisin-kexin-type-9-with-intima-media-thickness-in-patients-with-familial-hypercholesterolemia
#3
K S Benimetskaya, Yu I Ragino, E V Shakhtshneider, K V Makarenkova, Yu V Shchepina, E M Stakhneva, M I Voevoda
We studied association of PCSK9 protein with the carotid artery intima-media thickness in patients with familial hypercholesterolemia (N=53; age 49.9±6.9 years) treated with statins. Blood level of PCSK9 protein was measured by ELISA; ultrasonography of the carotid arteries with measurement of the thickness of the intima-media complex of the common carotid arteries in the distal segment for 10 mm from the bifurcation on the far wall of the vessel was performed in on-line mode. The mean values were calculated for both sides, the maximum mean value was included in the analysis...
July 18, 2017: Bulletin of Experimental Biology and Medicine
https://www.readbyqxmd.com/read/28725037/bursting-dynamics-in-the-normal-and-failing-hearts
#4
Vladimir E Bondarenko, Andrey L Shilnikov
A failing heart differs from healthy hearts by an array of symptomatic characteristics, including impaired Ca(2+) transients, upregulation of Na(+)/Ca(2+) exchanger function, reduction of Ca(2+) uptake to sarcoplasmic reticulum, reduced K(+) currents, and increased propensity to arrhythmias. While significant efforts have been made in both experimental studies and model development to display the causes of heart failure, the full process of deterioration from a healthy to a failing heart yet remains deficiently understood...
July 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28716911/activation-and-synchronization-of-the-oscillatory-morphodynamics-in-multicellular-monolayer
#5
Shao-Zhen Lin, Bo Li, Ganhui Lan, Xi-Qiao Feng
Oscillatory morphodynamics provides necessary mechanical cues for many multicellular processes. Owing to their collective nature, these processes require robustly coordinated dynamics of individual cells, which are often separated too distantly to communicate with each other through biomaterial transportation. Although it is known that the mechanical balance generally plays a significant role in the systems' morphologies, it remains elusive whether and how the mechanical components may contribute to the systems' collective morphodynamics...
July 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28715090/learning-based-automated-segmentation-of-the-carotid-artery-vessel-wall-in-dual-sequence-mri-using-subdivision-surface-fitting
#6
Shan Gao, Ronald Van't Klooster, Pieter H Kitslaar, Bram F Coolen, Alexandra M van den Berg, Loek P Smits, Rahil Shahzad, Denis P Shamonin, Patrick J H de Koning, Aart J Nederveen, Rob J van der Geest
PURPOSE: The quantification of vessel wall morphology and plaque burden requires vessel segmentation, which is generally performed by manual delineations. The purpose of our work is to develop and evaluate a new 3D model-based approach for carotid artery wall segmentation from dual-sequence MRI. METHODS: The proposed method segments the lumen and outer wall surfaces including the bifurcation region by fitting a subdivision surface constructed hierarchical-tree model to the image data...
July 17, 2017: Medical Physics
https://www.readbyqxmd.com/read/28714525/dedicated-bifurcation-stents-or-regular-drug-eluting-stents-in-distal-left-main-stenosis-a-retrospective-study
#7
Adam Kern, Robert J Gil, Krystian Bojko, Bartłomiej Rzeszowski, Krzysztof Bednarski, Jerzy Górny, Jacek Bil
BACKGROUND: Mainly atherosclerosis develops in distal left main (LM) within bifurcation or trifurcation. The aim of this study was to analyze the strategy of distal LM stenosis treatment and associated clinical outcomes in a large hospital in Northern Poland. METHODS: The study population consisted of consecutive patients with stable coronary artery disease or acute coronary syndrome (ACS) and distal LM stenosis who were hospitalized between June 2012 and June 2013...
July 17, 2017: Cardiology Journal
https://www.readbyqxmd.com/read/28713213/secondary-motion-in-three-dimensional-branching-networks
#8
Abhijit Guha, Kaustav Pradhan
A major aim of the present work is to understand and thoroughly document the generation, the three-dimensional distribution, and the evolution of the secondary motion as the fluid progresses downstream through a branched network. Six generations (G0-G5) of branches (involving 63 straight portions and 31 bifurcation modules) are computed in one go; such computational challenges are rarely taken in the literature. More than 30 × 10(6) computational elements are employed for high precision of computed results and fine quality of the flow visualization diagrams...
June 2017: Physics of Fluids
https://www.readbyqxmd.com/read/28712899/iatrogenic-ascending-pharyngeal-artery-injury-by-pre-dilation-balloon-inflation-during-carotid-artery-stenting-with-flow-reversal
#9
Junpei Koge, Tomonori Iwata, Shigehisa Mizuta, Yukihiko Nakamura, Shun-Ichi Matsumoto, Takeshi Yamada
BACKGROUND: The ascending pharyngeal artery (APA) may rarely arise from the common carotid artery bifurcation. We herein report an injury to the APA as an unusual complication of pre-dilation balloon inflation during carotid artery stenting (CAS) with flow reversal. CASE DESCRIPTION: A 73-year-old man presented with symptomatic severe left cervical internal carotid artery (ICA) stenosis. The left APA arose from the common carotid artery bifurcation. We performed CAS with flow reversal to decrease the risk of distal embolization...
July 13, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/28710373/a-method-for-validating-rent-s-rule-for-technological-and-biological-networks
#10
Fernando Alcalde Cuesta, Pablo González Sequeiros, Álvaro Lozano Rojo
Rent's rule is empirical power law introduced in an effort to describe and optimize the wiring complexity of computer logic graphs. It is known that brain and neuronal networks also obey Rent's rule, which is consistent with the idea that wiring costs play a fundamental role in brain evolution and development. Here we propose a method to validate this power law for a certain range of network partitions. This method is based on the bifurcation phenomenon that appears when the network is subjected to random alterations preserving its degree distribution...
July 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28709972/generalised-approach-to-modelling-a-three-tiered-microbial-food-web
#11
T Sari, M J Wade
The complexity of the anaerobic digestion process has motivated the development of complex models, such as the widely used Anaerobic Digestion Model No. 1. However, this complexity makes it intractable to identify the stability profile coupled to the asymptotic behaviour of existing steady-states as a function of conventional chemostat operating parameters (substrate inflow concentration and dilution rate). In a previous study this model was simplified and reduced to its very backbone to describe a three-tiered chlorophenol mineralising food-web, with its stability analysed numerically using consensus values for the various biological parameters of the Monod growth functions...
July 11, 2017: Mathematical Biosciences
https://www.readbyqxmd.com/read/28709917/what-triggers-in-trigger-finger-the-flexor-tendons-at-the-flexor-digitorum-superficialis-bifurcation
#12
X L Chuang, C C Ooi, S T Chin, M A Png, S K Wong, S C Tay, D A McGrouther
To define the role of the flexor tendons in trigger finger, a high-resolution ultrasound examination was performed in 20 trigger fingers and 20 normal contralateral digits in three digital postures: full extension, mid-flexion and near-full flexion. Precise measurements of diameter and cross-sectional area of the combined tendon mass were recorded at five clearly defined locations: summit of the metacarpal head, proximal lip of the proximal phalanx (PP) and at 1/8, 1/4 and 1/2 length of the PP. In the normal tendons, there was an anatomical thickening, not previously appreciated at 1/4 length PP, in the region of the FDS bifurcation...
May 27, 2017: Journal of Plastic, Reconstructive & Aesthetic Surgery: JPRAS
https://www.readbyqxmd.com/read/28709701/optical-coherence-tomography-guidance-for-the-management-of-angiographically-intermediate-left-main-bifurcation-lesions-early-clinical-experience
#13
Ilaria Dato, Francesco Burzotta, Carlo Trani, Andrea Romano, Lazzaro Paraggio, Cristina Aurigemma, Italo Porto, Antonio Maria Leone, Giampaolo Niccoli, Filippo Crea
BACKGROUND: Left main (LM) atherosclerotic lesions affect clinical outcomes. Frequency domain-optical coherence tomography (FD-OCT) allows detailed characterization of non-ostial coronary atherosclerotic lesions. The clinical impact of FD-OCT assessment of LM bifurcation disease on the revascularization decision is unknown. METHODS: Patients who underwent FD-OCT assessment to guide management of angiographically intermediate distal LM stenosis were retrospectively selected...
July 5, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28709358/analytic-solutions-throughout-a-period-doubling-route-to-chaos
#14
Marko S Milosavljevic, Jonathan N Blakely, Aubrey N Beal, Ned J Corron
We show examples of dynamical systems that can be solved analytically at any point along a period doubling route to chaos. Each system consists of a linear part oscillating about a set point and a nonlinear rule for regularly updating that set point. Previously it has been shown that such systems can be solved analytically even when the oscillations are chaotic. However, these solvable systems show few bifurcations, transitioning directly from a steady state to chaos. Here we show that a simple change to the rule for updating the set point allows for a greater variety of nonlinear dynamical phenomena, such as period doubling, while maintaining solvability...
June 2017: Physical Review. E
https://www.readbyqxmd.com/read/28709323/noise-induced-stabilization-of-collective-dynamics
#15
Pau Clusella, Antonio Politi
We illustrate a counterintuitive effect of an additive stochastic force, which acts independently on each element of an ensemble of globally coupled oscillators. We show that a very small white noise not only broadens the clusters, wherever they are induced by the deterministic forces, but can also stabilize a linearly unstable collective periodic regime: self-consistent partial synchrony. With the help of microscopic simulations we are able to identify two noise-induced bifurcations. A macroscopic analysis, based on a perturbative solution of the associated nonlinear Fokker-Planck equation, confirms the numerical studies and allows determining the eigenvalues of the stability problem...
June 2017: Physical Review. E
https://www.readbyqxmd.com/read/28709302/bifurcation-trees-of-stark-wannier-ladders-for-accelerated-bose-einstein-condensates-in-an-optical-lattice
#16
Andrea Sacchetti
In this paper we show that in the semiclassical regime of periodic potential large enough, the Stark-Wannier ladders become a dense energy spectrum because of a cascade of bifurcations while increasing the ratio between the effective nonlinearity strength and the tilt of the external field; this fact is associated to a transition from regular to quantum chaotic dynamics. The sequence of bifurcation points is explicitly given.
June 2017: Physical Review. E
https://www.readbyqxmd.com/read/28709282/hybrid-smoothed-dissipative-particle-dynamics-and-immersed-boundary-method-for-simulation-of-red-blood-cells-in-flows
#17
Ting Ye, Nhan Phan-Thien, Chwee Teck Lim, Lina Peng, Huixin Shi
In biofluid flow systems, often the flow problems of fluids of complex structures, such as the flow of red blood cells (RBCs) through complex capillary vessels, need to be considered. The smoothed dissipative particle dynamics (SDPD), a particle-based method, is one of the easy and flexible methods to model such complex structure fluids. It couples the best features of the smoothed particle hydrodynamics (SPH) and dissipative particle dynamics (DPD), with parameters having specific physical meaning (coming from SPH discretization of the Navier-Stokes equations), combined with thermal fluctuations in a mesoscale simulation, in a similar manner to the DPD...
June 2017: Physical Review. E
https://www.readbyqxmd.com/read/28709265/from-synchronous-to-one-time-delayed-dynamics-in-coupled-maps
#18
Celia Anteneodo, Juan Carlos González-Avella, Raúl O Vallejos
We study the completely synchronized states (CSSs) of a system of coupled logistic maps as a function of three parameters: interaction strength (ɛ), range of the interaction (α), that can vary from first neighbors to global coupling, and a parameter (β) that allows one to scan continuously from nondelayed to one-time delayed dynamics. In the α-ɛ plane we identify periodic orbits, limit cycles, and chaotic trajectories, and describe how these structures change with delay. These features can be explained by studying the bifurcation diagrams of a two-dimensional nondelayed map...
June 2017: Physical Review. E
https://www.readbyqxmd.com/read/28709250/nonlinear-dynamics-and-band-transport-in-a-superlattice-driven-by-a-plane-wave
#19
A Apostolakis, M K Awodele, K N Alekseev, F V Kusmartsev, A G Balanov
A quantum particle transport induced in a spatially periodic potential by a propagating plane wave has a number of important implications in a range of topical physical systems. Examples include acoustically driven semiconductor superlattices and cold atoms in an optical crystal. Here we apply a kinetic description of the directed transport in a superlattice beyond standard linear approximation, and utilize exact path-integral solutions of the semiclassical transport equation. We show that the particle drift and average velocities have nonmonotonic dependence on the wave amplitude with several prominent extrema...
June 2017: Physical Review. E
https://www.readbyqxmd.com/read/28709248/from-bulk-self-assembly-to-electrical-diffuse-layer-in-a-continuum-approach-for-ionic-liquids-the-impact-of-anion-and-cation-size-asymmetry
#20
Sariel Bier, Nir Gavish, Hannes Uecker, Arik Yochelis
Ionic liquids are solvent-free electrolytes, some of which possess an intriguing self-assembly at finite length scale due to Coulombic interactions. Using a continuum framework (based on Onsager's relations), it is shown that bulk nanostructures arise via linear (supercritical) and nonlinear (subcritical) bifurcations (morphological phase transitions), which also directly affect the electrical double layer structure. A Ginzburg-Landau amplitude equation is derived and the bifurcation type is related to model parameters, such as temperature, potential, and interactions...
June 2017: Physical Review. E
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