Search for Voids in a Reactor Calandria Sample by Means of Positron Annihilation and Electron Microscopy

1974 ◽  
Vol 52 (3) ◽  
pp. 278-280 ◽  
Author(s):  
S. M. Kim ◽  
W. J. L. Buyers ◽  
P. Martel ◽  
G. J. C. Carpenter
Keyword(s):  
Electron Microscopy ◽  
Angular Distribution ◽  
Electron Microscope ◽  
Positron Annihilation ◽  
Neutron Irradiation ◽  
Cold Working ◽  
Annealed Sample ◽  
Microscope Examination ◽  
Density Of Dislocations ◽  
Electron Microscope Examination

We have measured the positron annihilation angular distribution in 1S Al subjected to neutron irradiation while part of the NRX reactor calandria, in annealed IS Al, and in heavily deformed 1S Al, which simulates the cold working of the calandria sample before irradiation. The FWHM in the calandria and deformed samples were found to be similar and 11% narrower than that in the annealed sample, indicating that the dominant defects in the calandria are dislocations rather than voids. Electron microscope examination of the above samples also indicated a high density of dislocations and no significant void population in the neutron irradiated calandria.

In vitro development of isolated ectoderm from axolotl gastrulae

Development ◽  
1984 ◽  
Vol 80 (1) ◽  
pp. 321-330
Author(s):  
Jonathan M. W. Slack
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Outer Layer ◽  
Microscope Examination ◽  
Animal Pole ◽  
In Vitro Development ◽  
Electron Microscope Examination ◽  
Vitro Development

The development of ectoderm isolated from the animal pole of axolotl gastrulae is monitored by light microscopy, electron microscopy and analysis of newly synthesized proteins, glycoproteins and glycolipids. When control embryos are undergoing neurulation it is shown that the explants autonomously begin to express epidermal markers and do not express mesodermal markers. However the results suggest that not all the cells become epidermal and electron microscope examination shows that only the outer layer does so, the inner cells remaining undifferentiated.

Selective Sampling and Orientation of Non-Homogeneous Tissues

1968 ◽  
Vol 26 ◽  
pp. 98-99
Author(s):  
C. C. Clawson ◽  
L. W. Anderson ◽  
R. A. Good
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Random Sampling ◽  
New Method ◽  
Microscope Examination ◽  
Small Areas ◽  
Selective Sampling ◽  
Large Numbers ◽  
Specific Orientation

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.

scholarly journals A ZONAL ROTOR METHOD FOR THE PREPARATION OF MICROPEROXISOMES FROM EPITHELIAL CELLS OF GUINEA PIG SMALL INTESTINE

1974 ◽  
Vol 61 (1) ◽  
pp. 123-133 ◽  
Author(s):  
M. J. Connock ◽  
P. R. Kirk ◽  
A. P. Sturdee
Keyword(s):  
Small Intestine ◽  
Electron Microscope ◽  
Epithelial Cells ◽  
Guinea Pig ◽  
Analytical Data ◽  
Microscope Examination ◽  
Electron Microscope Examination ◽  
Large Particles ◽  
Zonal Separation ◽  
Zonal Rotor

A method is described for the preparation of catalase particles from homogenates made from suspensions of epithelial cells of the small intestine of the guinea pig. Electron microscope examination of the preparations revealed the presence of small diaminobenzidine-positive particles measuring 0.1–0.3 nm in diameter and resembling the microperoxisomes observed by Novikoff and Novikoff (1972. J. Cell Biol. 53:532.). Analytical data upon which the method is based are presented. The technique consisted of a rate zonal separation of microperoxisomes from large particles followed by an isopycnic separation from less dense organelles. Application of the method yielded microperoxisomes purified between 20- and 30-fold.

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