Phase contrast studies of (100) surfaces of MgO crystals during dissolution

Micron (1969) ◽  
1980 ◽  
Vol 11 (3-4) ◽  
pp. 301-302
Author(s):  
R.L. Segall ◽  
R.St.C. Smart ◽  
P.S. Turner ◽  
C.E. Warble
Keyword(s):  
Phase Contrast ◽  
Contrast Studies

Phase contrast studies of biological specimens with the x‐ray microscope at BESSY (invited)

1995 ◽  
Vol 66 (2) ◽  
pp. 1282-1286 ◽  
Author(s):  
Günter Schmahl ◽  
Dietbert Rudolph ◽  
Peter Guttmann ◽  
Gerd Schneider ◽  
Jürgen Thieme ◽  
...  
Keyword(s):  
Phase Contrast ◽  
X Ray ◽  
Contrast Studies

CYTOLOGY OF THE HUMAN AMNION: A CORRELATION WITH CELL CULTURE

1965 ◽  
Vol 11 (1) ◽  
pp. 39-44 ◽  
Author(s):  
J. C. Wilt ◽  
Donna Miller
Keyword(s):  
Cell Culture ◽  
Cell Separation ◽  
Phase Contrast ◽  
Human Amnion ◽  
Dark Cells ◽  
Amniotic Membranes ◽  
Vacuolated Cells ◽  
Contrast Studies

Phase-contrast studies on amnion cells in suspension following trypsinization of membranes showed the cells to be usually markedly vacuolated and highly refractile and the nucleus to be obscured; a few cells were non-vacuolated, dark, and smaller. Studies were initiated to determine the origin of the small dark cells and their growth in cell culture, utilizing a series of staining technics to elaborate the differences seen by phase-contrast microscopy.Biopsies of amniotic membranes from Caesarian sections more frequently showed less vacuolation of epithelium as compared to amnions from normal deliveries, which were usually markedly vacuolated; trypsinization of membranes made up of non-vacuolated epithelium yielded suspensions made up entirely of smaller, dark cells. Studies on the process of cell separation showed this change of the non-vacuolated cells to smaller dark cells to be an effect of trypsin. The small dark cells were superior to the vacuolated cells for culture purposes.

scholarly journals Adenosine and Spore Germination; Phase-contrast Studies

1951 ◽  
Vol 5 (4) ◽  
pp. 657-663 ◽  
Author(s):  
R. J. V. PULVERTAFT ◽  
J. A. HAYNES
Keyword(s):  
Spore Germination ◽  
Phase Contrast ◽  
Contrast Studies

Diffraction enhance x-ray imaging for quantitative phase contrast studies

2016 ◽  
Author(s):  
A. K. Agrawal ◽  
B. Singh ◽  
Y. S. Kashyap ◽  
Mayank Shukla ◽  
P. S. Sarkar ◽  
...  
Keyword(s):  
Phase Contrast ◽  
X Ray ◽  
Quantitative Phase ◽  
X Ray Imaging ◽  
Contrast Studies

Observation of biological macromolecules using various electron microscopic methods

1978 ◽  
Vol 36 (2) ◽  
pp. 170-171
Author(s):  
Mitsuo Ohtsuki ◽  
Michael Sogard
Keyword(s):  
Electron Microscope ◽  
Phase Contrast ◽  
Image Interpretation ◽  
Density Lipoprotein ◽  
Biological Macromolecules ◽  
Contrast Effects ◽  
Biological Structure ◽  
Electron Microscopic ◽  
Structural Investigations ◽  
Staining Techniques

Structural investigations of biological macromolecules commonly employ CTEM with negative staining techniques. Difficulties in valid image interpretation arise, however, due to problems such as variability in thickness and degree of penetration of the staining agent, noise from the supporting film, and artifacts from defocus phase contrast effects. In order to determine the effects of these variables on biological structure, as seen by the electron microscope, negative stained macromolecules of high density lipoprotein-3 (HDL3) from human serum were analyzed with both CTEM and STEM, and results were then compared with CTEM micrographs of freeze-etched HDL3. In addition, we altered the structure of this molecule by digesting away its phospholipid component with phospholipase A2 and look for consistent changes in structure.

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

The Imaging of Crystal Structures and Crystal Defects

1978 ◽  
Vol 36 (3) ◽  
pp. 207-217
Author(s):  
J.M. Cowley
Keyword(s):  
Electron Microscope ◽  
Crystal Structures ◽  
Phase Contrast ◽  
Crystal Defects ◽  
Atom Density ◽  
Lack Of Information ◽  
Spatial Frequencies

The problem of "understandinq" electron microscope imaqes becomes more acute as the resolution is improved. The naive interpretation of an imaqe as representinq the projection of an atom density becomes less and less appropriate. We are increasinqly forced to face the complexities of coherent imaqinq of what are essentially phase objects. Most electron microscopists are now aware that, for very thin weakly scatterinq objects such as thin unstained bioloqical specimens, hiqh resolution imaqes are best obtained near the optimum defocus, as prescribed by Scherzer, where the phase contrast imaqe qives a qood representation of the projected potential, apart from a lack of information on the lower spatial frequencies. But phase contrast imaqinq is never simple except in idealized limitinq cases.

Sign in / Sign up

Export Citation Format

Share Document