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Full-Text Articles in Life Sciences
Non-Equilibrium Surface Diffusion Measurements In Systems With Interactions, M. C. Tringides, K. R. Roos, A. Jesina, J. Haas, P. Levenberg
Non-Equilibrium Surface Diffusion Measurements In Systems With Interactions, M. C. Tringides, K. R. Roos, A. Jesina, J. Haas, P. Levenberg
Scanning Microscopy
Diffusion in surface overlayers with adsorbate-adsorbate interactions is described in terms of coverage-dependent diffusion coefficients. The measured phenomenological Arrhenius parameters (activation energy and prefactor) depend on the initial configuration of the system. Since different experimental methods probe the system in different states, the measured diffusion coefficients depend on the method used. Experimental results demonstrating this dependence are presented for O/W(110) -p(2x1) + p(2x2) and Ag/Si(111) -√3 x √3 R30°. They were measured during the evolution of the system to attain a new equilibrium state of different symmetry. In addition, simulations on lattice gas models with interactions, modeling …
Growth Of Yba2cu3o7-Δ Thin-Films–Nucleation, Heteroepitaxy And Interfaces, M. Grant Norton, C. Barry Carter
Growth Of Yba2cu3o7-Δ Thin-Films–Nucleation, Heteroepitaxy And Interfaces, M. Grant Norton, C. Barry Carter
Scanning Microscopy
A major research effort in high-temperature oxide superconductors is the growth of high-quality thin-films. The physical properties of polycrystalline thin-films are controlled by their microstructure which is influenced by the early stages of film growth and the establishment of epitaxy. In this article, the nucleation and heteroepitactic growth of YBa2Cu3O7-δ thin-films is reviewed. Many of the examples illustrating film growth will be taken from studies using transmission electron microscopy. The importance of the substrate surface in controlling film growth will be discussed, in particular the growth of YBa2Cu3O7-δ films on …
Responses Of Astrocytes In Culture After Low Dose Laser Irradiation, David T. Yew, D. R. Zheng, C. Au, W. W. Y. Li
Responses Of Astrocytes In Culture After Low Dose Laser Irradiation, David T. Yew, D. R. Zheng, C. Au, W. W. Y. Li
Scanning Microscopy
The effect of Helium-Neon low dose laser on astrocytes was investigated in cultures of isolated astrocytes from albino neonatal rats. The laser appeared to inhibit the growth of astrocytes as exemplified by the smaller sizes of the cells and the decreased leucine uptake in each cell after treatment. Temporary decrease in the number of mitoses was also observed, but this trend was reversed soon after. Electron microscopic studies revealed an increase in buddings from cell bodies and processes (branches) after irradiation.
The Study Of Biominerals By High Resolution Transmission Electron Microscopy, Stephen Mann
The Study Of Biominerals By High Resolution Transmission Electron Microscopy, Stephen Mann
Scanning Electron Microscopy
This paper presents an overview of the study of the ultrastructure of biogenic inorganic solids (biominerals) using high resolution transmission electron microscopy (HRTEM). A range of biominerals have been studied including iron oxides, calcium phosphates, calcium carbonates and silica. The studies have revealed information concerning the structural complexity of these materials and have identified crystallographic order and disorder at the nanometre level. In addition, the results have aided the elucidation of the mechanisms of nucleation and growth of biogenic minerals.