Isolation of pulmonary veins using a thermoreactive implantable device with external energy transfer: Evaluation in a porcine model

2018 ◽  
Vol 41 (6) ◽  
pp. 603-610 ◽  
Author(s):  
Tim Boussy ◽  
Tim Vandecasteele ◽  
Lisse Vera ◽  
Stijn Schauvliege ◽  
Matthew Philpott ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Porcine Model ◽  
Pulmonary Veins ◽  
Implantable Device ◽  
External Energy

Available potential energy and buoyancy variance in horizontal convection

2009 ◽  
Vol 629 ◽  
pp. 221-230 ◽  
Author(s):  
KRAIG B. WINTERS ◽  
WILLIAM R. YOUNG
Keyword(s):  
Energy Transfer ◽  
Potential Energy ◽  
Energy Budget ◽  
Molecular Diffusion ◽  
Thought Experiment ◽  
Mechanical Energy ◽  
External Energy ◽  
Additional Energy ◽  
Transfer Rates ◽  
Available Potential Energy

We consider the mechanical energy budget for horizontal Boussinesq convection and show that there are two distinct energy pathways connecting the mechanical energy (i.e. kinetic, available potential and background potential energies) to the internal energy reservoir and the external energy source. To obtain bounds on the magnitudes of the energy transfer rates around each cycle, we first show that the volume-averaged dissipation rate of buoyancy variance χ ≡ κ 〈|∇b|2〉, where b is the buoyancy, is bounded from above by 4.57h−1κ2/3ν−1/3b7/3max. Here h is the depth of the container, κ the molecular diffusion, ν the kinematic viscosity and bmax the maximum buoyancy difference that exists on the surface. The bound on χ is used to estimate the generation rate of available potential energy Ea and the rate at which Ea is irreversibly converted to background potential energy via diapycnal fluxes, both of which are shown to vanish at least as fast as κ1/3 in the limit κ → 0 at fixed Prandtl number Pr = ν/κ. As a thought experiment, consider a hypothetical ocean insulated at all boundaries except at the upper surface, where the buoyancy is prescribed. The bounds on the energy transfer rates in the mechanical energy budget imply that buoyancy forcing alone is insufficient by at least three orders of magnitude to maintain observed oceanic dissipation rates and that additional energy sources such as winds, tides and perhaps bioturbation are necessary to sustain observed levels of turbulent dissipation in the world's oceans.

External energy transfer in amplified spontaneous emissions from MEH-PPV conjugated polymer

2011 ◽  
Vol 43 (1) ◽  
pp. 147-151 ◽  
Author(s):  
Mohamad S. Alsalhi ◽  
Ziyad S. Abu Mustafa ◽  
V. Masilamani
Keyword(s):  
Energy Transfer ◽  
Conjugated Polymer ◽  
External Energy ◽  
Spontaneous Emissions

Efficient External Energy Transfer from Mn-Doped Perovskite Nanocrystals

2021 ◽  
Vol 12 (5) ◽  
pp. 1475-1480
Author(s):  
Shiping Wang ◽  
Jing Leng ◽  
Qi Sun ◽  
Chunyi Zhao ◽  
Shengye Jin
Keyword(s):  
Energy Transfer ◽  
External Energy ◽  
Perovskite Nanocrystals ◽  
Mn Doped

Histopathological Evaluation of a Novel Radiofrequency Surgical Ablation System

2008 ◽  
Vol 3 (2) ◽  
pp. 47-51 ◽  
Author(s):  
Adam E. Saltman ◽  
Narayan R. Raju ◽  
Jon E. Block
Keyword(s):  
Thermal Injury ◽  
Porcine Model ◽  
Pulmonary Veins ◽  
Myocardial Necrosis ◽  
Beating Heart ◽  
Section Thickness ◽  
Surgical Ablation ◽  
Lesion Depth ◽  
Epicardial Surface ◽  
Histopathological Evaluation

Purpose Using a porcine model, this feasibility study was undertaken to evaluate the histopathological characteristics of lesions created in the proximity of the pulmonary veins after ablation with a new endoscopic-guided radiofrequency device. Methods Five adult female swine underwent endoscopic surgical ablation on the epicardial surface of the beating heart. Histologic sections taken from around the pulmonary vein pedicle, representing 10 separate anatomic sites, underwent independent qualitative histopathological evaluation as well as quantitative histomorphometric measurement of lesion depth and section thickness. Results Sections from all five animals had histologically identical lesions, with the majority of ablation foci having pronounced thermal injury characterized by deep and extensive zones of acute myocardial necrosis in the absence of tissue charring. Fifty-seven percent (13 of 23) of the lesions were completely transmural and 91% (21 of 23) of the sections demonstrated ≥70% transmurality. No collateral injuries were noted. Conclusions This irrigated, suction-stabilized unipolar radiofrequency device can produce histologically transmural lesions around the pulmonary veins and is amenable to endoscopic-guided application on the beating heart.

A quantitative approach to inner shell losses

1978 ◽  
Vol 36 (1) ◽  
pp. 526-527 ◽  
Author(s):  
R.D. Leapman ◽  
P. Rez ◽  
D.F. Mayers
Keyword(s):  
Energy Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Accurate Determination ◽  
Background Intensity ◽  
Core Excitation ◽  
Quantitative Basis ◽  
Cross Section Differential ◽  
Bound Electrons

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as

Molecular and Microscopic Analysis of Altered Gene Expression in Transgenic and Gene Targeted Mice

1996 ◽  
Vol 54 ◽  
pp. 12-13
Author(s):  
W. K. Jones ◽  
J. Robbins
Keyword(s):  
Gene Expression ◽  
Pulmonary Veins ◽  
Microscopic Analysis ◽  
Mouse Tissue ◽  
Adult Heart ◽  
Heavy Chains ◽  
Altered Gene Expression ◽  
Altered Gene ◽  
Pulmonary Myocardium

Two myosin heavy chains (MyHC) are expressed in the mammalian heart and are differentially regulated during development. In the mouse, the α-MyHC is expressed constitutively in the atrium. At birth, the β-MyHC is downregulated and replaced by the α-MyHC, which is the sole cardiac MyHC isoform in the adult heart. We have employed transgenic and gene-targeting methodologies to study the regulation of cardiac MyHC gene expression and the functional and developmental consequences of altered α-MyHC expression in the mouse.We previously characterized an α-MyHC promoter capable of driving tissue-specific and developmentally correct expression of a CAT (chloramphenicol acetyltransferase) marker in the mouse. Tissue surveys detected a small amount of CAT activity in the lung (Fig. 1a). The results of in situ hybridization analyses indicated that the pattern of CAT transcript in the adult heart (Fig. 1b, top panel) is the same as that of α-MyHC (Fig. 1b, lower panel). The α-MyHC gene is expressed in a layer of cardiac muscle (pulmonary myocardium) associated with the pulmonary veins (Fig. 1c). These studies extend our understanding of α-MyHC expression and delimit a third cardiac compartment.

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