The finite element method (FEM) based on a nonregular mesh is used to solve Hartree-Fock and Kohn-Sham equations for three atoms (hydrogen, helium, and beryllium) confined by finite and infinite potentials, defined in terms of piecewise functions or functions with a well-defined first derivative. This approach's reliability is shown when contrasted with Roothaan's approach, which depends on a basis set. Therefore, its exponents must be optimized for each confinement imposed over each atom, which is a monumental task. The comparison between our numerical approach and Roothaan's approach is made by using total and orbitals energies from the Hartree-Fock method, where there are several comparison sources. Regarding the Kohn-Sham method, there are few published data and consequently the results reported here can be used as a benchmark for future comparisons. The way to solve Hartree-Fock or Kohn-Sham equations by the FEM is entirely appropriate to study confined atoms with any form of confinement potential. This article represents a step toward developing a fully numerical quantum chemistry code free of basis sets to obtain the electronic structure of many-electron atoms confined by arbitrary confinement.
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http://dx.doi.org/10.1103/PhysRevE.108.035302 | DOI Listing |
J Biomed Mater Res A
January 2025
Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw, Poland.
Bone tissue regeneration can be affected by various architectonical features of 3D porous scaffold, for example, pore size and shape, strut size, curvature, or porosity. However, the design of additively manufactured structures studied so far was based on uniform geometrical figures and unit cell structures, which often do not resemble the natural architecture of cancellous bone. Therefore, the aim of this study was to investigate the effect of architectonical features of additively manufactured (aka 3D printed) titanium scaffolds designed based on microtomographic scans of fragments of human femurs of individuals of different ages on in vitro response of human bone-derived mesenchymal stem cells (hMSC).
View Article and Find Full Text PDFFront Bioeng Biotechnol
December 2024
Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand.
In this work, a cost-effective, scalable pneumatic silicone actuator array is introduced, designed to dynamically conform to the user's skin and thereby alleviate localised pressure within a prosthetic socket. The appropriate constitutive models for developing a finite element representation of these actuators are systematically identified, parametrised, and validated. Employing this computational framework, the surface deformation fields induced by 270 variations in soft actuator array design parameters under realistic load conditions are examined, achieving predictive accuracies within 70 µm.
View Article and Find Full Text PDFAsian Spine J
December 2024
Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA.
Study Design: This study employed a patient-specific finite element model.
Purpose: To quantify the effect of anterior and posterior surgical approaches on adjacent segment biomechanics of the patient-specific spine and spinal cord.
Overview Of Literature: Adjacent segment degeneration (ASD) is a well-documented complication following cervical fusion, typically resulting from accelerated osteoligamentous deterioration and subsequent symptomatic neural compression.
ACS Sens
January 2025
College of Chemistry, Beijing Normal University, Beijing 100875, China.
Iontronic sensors based on confined space have garnered significant attention due to their promising applications, ranging from single-cell analysis to studies. However, their limited sensitivity has constrained their effectiveness in studying molecular information during physiological and pathological processes. Here, we demonstrate an electrolyte-gated ionic transistor (EGIT) by integrating the confined ion transport behavior in a double-barreled micropipet with an electrolyte-gated transistor configuration, achieving highly sensitive and selective sensing.
View Article and Find Full Text PDFSmall
January 2025
Engineering Research Center of Western Resource Innovation Medicine Green Manufacturing, Ministry of Education, School of Chemical Engineering, Northwest University, Xi'an, 710127, China.
Flexible wearable sensors with bimodal functionality offer substantial value for human health monitoring, as relying on a single indicator is insufficient for capturing comprehensive physiological information. However, bimodal sensors face multiple challenges in practical applications, including mutual interference between various modalities, and integration of excellent mechanical properties, interfacial adhesion, environmental adaptability and biocompatibility. Herein, the multifunctional hydrogel, synthesized through radical grafting and supramolecular self-crosslinking reactions, exhibits excellent thermal sensitivity (TCR = -1.
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