Physical Mechanisms for Electromagnetic Interaction with Biological Systems

1989 ◽  
pp. 179-211 ◽  
Author(s):  
Paolo Bernardi ◽  
Guglielmo D’Inzeo
Keyword(s):  
Electromagnetic Interaction ◽  
Biological Systems ◽  
Physical Mechanisms

Uncovering the underlying physical mechanisms of biological systems via quantification of landscape and flux

2016 ◽  
Vol 25 (1) ◽  
pp. 016401 ◽  
Author(s):  
Li Xu ◽  
Xiakun Chu ◽  
Zhiqiang Yan ◽  
Xiliang Zheng ◽  
Kun Zhang ◽  
...  
Keyword(s):  
Biological Systems ◽  
Physical Mechanisms

scholarly journals Ponderomotive Forces in the System of Two Nanoparticles

2021 ◽  
Author(s):  
Valeri Z. Lozovski ◽  
Volodymyr S. Lysenko ◽  
Natalia Rusinchuk
Keyword(s):  
Local Field ◽  
Electromagnetic Interaction ◽  
Biological Systems ◽  
Field Enhancement ◽  
Enhancement Effect ◽  
Local Field Enhancement ◽  
Field Gradients ◽  
Ponderomotive Forces

Abstract Mechanical consequences of electromagnetic interaction of two nanoparticles have been studied theoretically. It has been shown that local field enhancement effect, which causes appearance of the local field gradients, can lead to ponderomotive forces acting on the nanoparticles. Distribution of the local field in the system has been calculated and ponderomotive forces directions and values were evaluated. It has been shown that in the system of two different-sized nanoparticles the forces act mainly on the surface of bigger nanoparticle and for some systems its value may acquire up to several tens of nanonewtons. Possible application of the results to study of biological systems has been also discussed.

Transmission Electron Microscopy of Protein Macromolecules

1971 ◽  
Vol 29 ◽  
pp. 424-425
Author(s):  
Henry S. Slayter
Keyword(s):  
Biological Systems ◽  
Metal Vapor ◽  
Resolving Power ◽  
Electron Microscopic ◽  
Chemical Methods ◽  
Molecular Weights ◽  
The Past ◽  
Physical Chemical ◽  
Transmission Electron

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.

Strain analysis with nanometer resolution using a conventional transmission electron microsopy technique: electron diffraction contrast imaging revisited

1995 ◽  
Vol 53 ◽  
pp. 168-169
Author(s):  
Koenraad G F Janssens ◽  
Omer Van der Biest ◽  
Jan Vanhellemont ◽  
Herman E Maes ◽  
Robert Hull
Keyword(s):  
Electron Diffraction ◽  
Strain Field ◽  
Elastic Strain ◽  
Strain Analysis ◽  
Local Strain ◽  
Contrast Imaging ◽  
Strain Characterization ◽  
Physical Mechanisms ◽  
Diffraction Contrast ◽  
Transmission Electron

There is a growing need for elastic strain characterization techniques with submicrometer resolution in several engineering technologies. In advanced material science and engineering the quantitative knowledge of elastic strain, e.g. at small particles or fibers in reinforced composite materials, can lead to a better understanding of the underlying physical mechanisms and thus to an optimization of material production processes. In advanced semiconductor processing and technology, the current size of micro-electronic devices requires an increasing effort in the analysis and characterization of localized strain. More than 30 years have passed since electron diffraction contrast imaging (EDCI) was used for the first time to analyse the local strain field in and around small coherent precipitates1. In later stages the same technique was used to identify straight dislocations by simulating the EDCI contrast resulting from the strain field of a dislocation and comparing it with experimental observations. Since then the technique was developed further by a small number of researchers, most of whom programmed their own dedicated algorithms to solve the problem of EDCI image simulation for the particular problem they were studying at the time.

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