An approach to analyzing and quantifying the shape characteristics of the endocardial contour of the left ventricle of the heart is described. The computation begins by finding the local curvature differences between the contour under consideration and the mean normal contour at each of 100 equidistant points. The weighted square of these differences, summed over a set of points, is shown to be the regional or, global bending energy required to deform the mean normal contour to the characteristic shape of the analyzed contour. Resampling, smoothing and curvature computation issues are considered for the image-derived digital contours that are used in the analysis. Experiments were performed on artificial contour data and data derived from contrast ventriculographic (CV) studies of humans. It is also shown that the method has been adapted to measure endocardial shape form equilibrium radionuclide angiocardiography.
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http://dx.doi.org/10.1109/42.97580 | DOI Listing |
Biophys J
January 2025
Theoretical Physics of Living Matter, Institute of Biological Information Processing and Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany. Electronic address:
Translocation across barriers and through constrictions is a mechanism that is often used in vivo for transporting material between compartments. A specific example is apicomplexan parasites invading host cells through the tight junction that acts as a pore, and a similar barrier crossing is involved in drug delivery using lipid vesicles penetrating intact skin. Here, we use triangulated membranes and energy minimization to study the translocation of vesicles through pores with fixed radii.
View Article and Find Full Text PDFSensors (Basel)
January 2025
Department of Civil Engineering, Myongji College, Seoul 03656, Republic of Korea.
Conventional approaches for the structural health monitoring of infrastructures often rely on physical sensors or targets attached to structural members, which require considerable preparation, maintenance, and operational effort, including continuous on-site adjustments. This paper presents an image-driven hybrid structural analysis technique that combines digital image processing (DIP) and regression analysis with a continuum point cloud method (CPCM) built on a particle-based strong formulation. Polynomial regressions capture the boundary shape change due to the structural loading and precisely identify the edge and corner coordinates of the deformed structure.
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January 2025
Chemistry Department, Moscow State University, Moscow 119991, Russia.
ZnO/MO (M = Fe, Co, Ni, Sn, In, Ga; [M]/([Zn] + [M]) = 15 mol%) nanofiber heterostructures were obtained by co-electrospinning and characterized by X-ray diffraction, scanning electron microscopy and X-ray fluorescence spectroscopy. The sensor properties of ZnO and ZnO/MO nanofibers were studied toward reducing gases CO (20 ppm), methanol (20 ppm), acetone (20 ppm), and oxidizing gas NO (1 ppm) in dry air. It was demonstrated that the temperature of the maximum sensor response of ZnO/MO nanofibers toward reducing gases is primarily influenced by the binding energy of chemisorbed oxygen with the surface of the modifier's oxides.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Laboratory for Testing and Materials, Department of Mechanics, School of Applied Mathematical and Physical Sciences, National Technical University of Athens, Zografou Campus, 157 73 Athens, Greece.
The fracture process of heterogeneous materials is studied here in the framework of the discipline of Non-Extensive Statistical Mechanics. Acoustic emission data provided by an experimental protocol with concrete specimens, plain or fiber-reinforced, under bending are taken advantage of. This innovation of the study lies in the fact that the analysis of the acoustic activity is implemented in terms of the energy content of the acoustic signals rather than of their interevent time or their interevent distance.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
School of Automobile and Traffic Engineering, Wuhan University of Science and Technology, Wuhan 430081, China.
The Diamond lattice cylindrical shell (Diamond LCS) was proposed by a mapping approach based on the triply periodic minimal surfaces (TPMS). The finite element models were built and their accuracy was verified by experimental results. Parameter studies were carried out to investigate the effect of geometric and loading parameters on the bending properties of the Diamond LCSs by the finite element model.
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