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Full-Text Articles in Life Sciences
Quantitative And Computer Assisted Electron Microscopic And Microprobe Studies In Dermatology, B. Forslind, A. Emilson
Quantitative And Computer Assisted Electron Microscopic And Microprobe Studies In Dermatology, B. Forslind, A. Emilson
Scanning Microscopy
Electron microscopes are not yet routine instruments in modern dermatological pathology even though they have provided detailed data about pathological changes in the skin for more than three decades. At present, dermatopathology is still dominated by light microscopy and especially so since the introduction of immunological techniques such as the use of monoclonal antibodies. These tools applied at electron microscopic resolution, however, may provide the ultimate identification of cells and subcellular components. In addition, electron microscopes have no peers in areas of quantitative investigation at subcellular levels, e.g. morphometry.
The electron microprobe provides a unique tool in elemental analysis and …
Functional And Morphological Studies Of Mitochondria Exposed To Undecagold Clusters: Biologic Surfaces Labeling With Gold Clusters, E. Valdivia, C. Gabel, J. E. Reardon, C. A. Cajacob, H. Yang, R. S. Wehbi, G. L. Scott, P. A. Frey, L. A. Fahien
Functional And Morphological Studies Of Mitochondria Exposed To Undecagold Clusters: Biologic Surfaces Labeling With Gold Clusters, E. Valdivia, C. Gabel, J. E. Reardon, C. A. Cajacob, H. Yang, R. S. Wehbi, G. L. Scott, P. A. Frey, L. A. Fahien
Scanning Microscopy
This study reports morphological and functional alterations observed in respiring isolated mitochondria when they are exposed to nonpenetrating, positive electrostatically charged synthetic undecagold clusters. Modification of the undecagold clusters positive charges change or prevent the functional effects and the binding to the outside surface of the mitochondria. The mitochondrial functional alterations are dependent on the oxidative phosphorylation capacity of the isolated organelles. The results of these experiments indicate that artificial undecagold may be useful to explore the molecular mechanisms of biological energy transducers which require electric charges separation, ionic fluxes, and electric surface properties.
Structure Of Rat Kidneys Following Microwave Accelerated Fixation, Jayashree A. Gokhale, Saeed R. Khan
Structure Of Rat Kidneys Following Microwave Accelerated Fixation, Jayashree A. Gokhale, Saeed R. Khan
Scanning Microscopy
In contrast to fixation of tissue in externally heated fixative, microwave-irradiation can generate uniform internal heat, which is of utmost importance for successful fixation of biological tissue. To evaluate the effectiveness of microwave-accelerated chemical fixation, we compared the structure of rat kidney fixed by a conventional method and a microwave-accelerated method, by scanning and transmission electron microscopy. Following perfusion, rat kidney pieces 1-2 mm in size were irradiated in Karnovsky's fixative in a domestic Amana microwave oven, till the temperature of the fixative reached 45-50°C. For conventional fixation, tissue pieces were fixed overnight at room temperature in the same fixative. …
Acquisition Hardware For Imaging, Peter Rez, J. K. Weiss, W. J. De Ruijter
Acquisition Hardware For Imaging, Peter Rez, J. K. Weiss, W. J. De Ruijter
Scanning Microscopy
In electron microscopy images can either be recorded in parallel (Transmission Electron Microscopy) or acquired as the variation in a signal as a probe is scanned over the specimen (Scanning Electron Microscopy). To extract the most information from an image requires that the best possible systems are used for acquiring image data. Ultimately, the limit to information capture is achieved when every electron from the scattering event of interest is recorded. The ideal system can be realised both for parallel recording with scientific grade CCD cameras, and for scanning microscopy with single electron counting electronics. The data rates from these …
Application Of The Wavelet Transform To The Digital Image Processing Of Electron Micrographs And Of Backreflection Electron Diffraction Patterns, A. Gómez, L. Beltrán Del Río, D. Romeu, M. Jose Yacamán
Application Of The Wavelet Transform To The Digital Image Processing Of Electron Micrographs And Of Backreflection Electron Diffraction Patterns, A. Gómez, L. Beltrán Del Río, D. Romeu, M. Jose Yacamán
Scanning Microscopy
In this work we explore the use of the so-called wavelet transform in the digital image processing of micrographs. The wavelet transform of an image f(x,y) is defined as:
Wf(s,u,v)
= f(x,y) s Ψ(s(x-u),s(y-v)) dxdy
where Ψ is an analyzing function called "wavelet" and which is in our examples always taken to be the "Mexican hat" given by
Ψ(x)=(2-(x2+y2))exp(-(x2+y2)/2)
Some synthetic images are shown in which it can be clearly seen how the wavelet transform can be useful to reveal edges and to emphasize the boundaries of the clusters.
The technique is …
The Application Of Multispectral Techniques To Analytical Electron Microscopy, P. G. Kenny, M. Prutton, R. H. Roberts, I. R. Barkshire, J. C. Greenwood, M. J. Hadley, S. P. Tear
The Application Of Multispectral Techniques To Analytical Electron Microscopy, P. G. Kenny, M. Prutton, R. H. Roberts, I. R. Barkshire, J. C. Greenwood, M. J. Hadley, S. P. Tear
Scanning Microscopy
The York multispectral analytical electron microscope (MULSAM) was the first instrument specifically designed to acquire and process multiple Auger, X-ray, backscattered electron, elastically scattered electron, scanning electron microscopy (SEM) and specimen absorption current images simultaneously. Analyzing combinations of these signals with multispectral correlation techniques yields more information than would normally be obtained by treating each image separately. This paper reports some of the multispectral methods we have investigated at York which may be of use to other workers. Included are (1) a method that corrects for beam current fluctuations during long acquisition runs which is based on the anti-correlation between …
Atomic Resolution Electron Holography, K. Ishizuka, T. Tanji, A. Tonomura
Atomic Resolution Electron Holography, K. Ishizuka, T. Tanji, A. Tonomura
Scanning Microscopy
It has been demonstrated that electron holography is a very powerful tool to investigate an electromagnetic potential in medium resolution, since the phase of an electron wave is approximately proportional to the potential. Now, electron holography is at the second stage of development: to establish holography at atomic resolution and further to realize Gabor's idea to improve the resolution restricted by the spherical aberration of the objective lens. We investigate the possibility of electron holography to get information at atomic resolution by computer simulations as well as by digital processing of electron holograms. We show that the phase distribution has …
Phase Space Methods In Image Formation Theory, Victor Castaño, Gustavo Vásquez-Polo, Ramón Gutiérrez-Castrejón
Phase Space Methods In Image Formation Theory, Victor Castaño, Gustavo Vásquez-Polo, Ramón Gutiérrez-Castrejón
Scanning Microscopy
A review of the basic mathematical principles and properties of some phase space functions (Wigner and Ambiguity functions) is first presented in a more general mathematical context. Then, we deal in detail with three applications : image formation in optical systems (specifically cascading systems of lenses), image formation in Transmission Electron Microscopy, by taking advantage of some formal similarities with the previous examples and, finally, contrast transfer functions in Electron Microscopy in order to obtain 2-dimensional plots which provide information on the behavior of a transmission electron microscope. Also, the relations of these functions with other mathematical tools utilized in …
Segmentation Of Pores In Backscattered Images Of Sediments And Soils And Their Relationship To Domain Structure, M. W. Hounslow, N. K. Tovey
Segmentation Of Pores In Backscattered Images Of Sediments And Soils And Their Relationship To Domain Structure, M. W. Hounslow, N. K. Tovey
Scanning Microscopy
A new technique to quantify variations in pore structure across an image is described in this paper. The method involves several stages as the original images are rarely suitable for simple segmentation by the selection of a single threshold. The processing first involves the application of a Wiener filter to remove imaging artefacts and to sharpen the edge of void/particle contacts. This image reconstruction is followed by the selection of a global threshold based on the relative contrast method, to create a binary image separating the voids from the particles. Such an image can be used to evaluate pore structure …
Digital Image Processing Of Electron Micrographs: The Pic System Ii, Benes L. Trus, Michael Unser, Thierry Pun, Alasdair C. Steven
Digital Image Processing Of Electron Micrographs: The Pic System Ii, Benes L. Trus, Michael Unser, Thierry Pun, Alasdair C. Steven
Scanning Microscopy
The PIC system, an integrated package of Fortran programs and subroutines designed to run on the Digital Equipment Corporation VAX family of computers, has been developed for analysis of electron micrographs with emphasis on the particular requirements for structural analysis of biological macromolecules. The substantially improved VAX version of PIC reported here has been developed from an earlier PDP-11 version which was, in turn, developed from a set of IBM 370 programs called MDPP. PIC now encompasses over 150 commands or processing operations that afford a comprehensive range of image processing operations including image restoration, enhancement, Fourier analysis, correlation averaging, …