scholarly journals SENSITIVITY IN ELECTRON MICROSCOPE AUTORADIOGRAPHY I. THE EFFECT OF RADIATION DOSE

1972 ◽  
Vol 20 (6) ◽  
pp. 425-434 ◽  
Author(s):  
MIRIAM M. SALPETER ◽  
MARIA SZABO
Keyword(s):  
Ascorbic Acid ◽  
Electron Microscope ◽  
Radiation Dose ◽  
Surface Area ◽  
Test Specimen ◽  
Dose Dependence ◽  
Unit Surface Area ◽  
Electron Microscope Autoradiography ◽  
Microscope Autoradiography ◽  
Unit Surface

Sensitivity in electron microscope autoradiography using Ilford L4 emulsion was shown to be affected by radiation dose ( i.e., number of decays in test specimen per unit surface area). The sensitivity tended to be higher with lower doses. This dose dependence was most marked with Microdol X and least with gold latensification-Elon ascorbic acid development. Possible consequences for quantitation in electron microscope autoradiography are discussed.

scholarly journals SENSITIVITY IN ELECTRON MICROSCOPE AUTORADIOGRAPHY FOR 125I

1974 ◽  
Vol 22 (2) ◽  
pp. 80-87 ◽  
Author(s):  
HELEN C. FERTUCK ◽  
MIRIAM M. SALPETER
Keyword(s):  
Heavy Metal ◽  
Electron Microscope ◽  
Radiation Dose ◽  
Dose Dependence ◽  
Specimen Thickness ◽  
Section Thickness ◽  
Electron Microscope Autoradiography ◽  
Absorption Studies ◽  
Microscope Autoradiography ◽  
Better Than

Sensitivity in electron microscope autoradiography was determined for 125I. Values are given using Ilford L4 and Kodak NTE emulsions combined with different developers. The extent of self-absorption as a function of section thickness and heavy metal staining and the effect of radiation dose (dose dependence) were assessed. It was found that the over-all efficiency for 125I was better than that for tritium and that, as is the case with tritium, there is a distinct "dose dependence" especially when Microdol X is the developer. Self-absorption studies indicate that self-absorption is increased by about 15% when the specimen thickness is increased from 300 to 1000 Å. An increase of under 15% is also introduced by heavy metal staining of sections in this thickness range.

scholarly journals Sensitivity in electron microscope autoradiography for calcium-45.

1980 ◽  
Vol 28 (1) ◽  
pp. 40-44 ◽  
Author(s):  
W V Harris ◽  
M M Salpeter
Keyword(s):  
Electron Microscope ◽  
Radiation Dose ◽  
Double Layers ◽  
Electron Microscope Autoradiography ◽  
Microscope Autoradiography

The sensitivity of Ilford L4 emulsion to 45Ca was determined for electron microscope autoradiographic conditions. Sensitivity values were obtained for monolayers and double layers of emulsion in combination with various developing procedures. The dependence of sensitivity upon radiation dose was determined. All results are compared to previously calibrated isotopes.

scholarly journals Acetylcholinesterase in the fast extraocular muscle of the mouse by light and electron microscope autoradiography.

1978 ◽  
Vol 78 (1) ◽  
pp. 274-285 ◽  
Author(s):  
M M Salpeter ◽  
A W Rogers ◽  
H Kasprzak ◽  
F A McHenry
Keyword(s):  
Electron Microscope ◽  
Surface Area ◽  
Binding Sites ◽  
Extraocular Muscle ◽  
Extraocular Muscles ◽  
Axonal Membrane ◽  
Electron Microscope Autoradiography ◽  
Diisopropyl Fluorophosphate ◽  
Speed Of Response ◽  
Microscope Autoradiography

The distribution of acetylcholinesterase (ACHe) in the twitch fibers of the extraocular muscles of the mouse was examined by light and electron microscope autoradiography after labeling with radioactive diisopropyl fluorophosphate (DFP) with, and without, 2-pyridine aldoxime methiodide (2-PAM) reactivation. The values obtained were compared with those previously reported for the diaphragm and sternomastoid muscles. The extraocular muscles were studied because they differ from the other two muscles in that they are among the fastest of the mammalian muscles, yet their endplates have sparse junctional folds. They could thus provide information on the extent to which ACHe concentration is an invariant feature of endplate morphology and what, if any aspects may be related to their fast speed of response. We found, using light microscope autoradiography, that in the twitch fibers of the extraocular muscle, there is n average of 6.4 +/- 2.1 X 10(7) DFP-binding sites per endplate, of which 29% (1.8 X 10(7)) are reactivated by 2-PAM and are thus AChe. The morphology of the extraocular endplates allowed us to conclude, on statistical grounds, that the AChe site are probably localized not only along the surface area of the postjunctional membrane (PJM) but also along the surface of the presynaptic axonal membrane. Based on this localization, we calculate 7,800 DFP sites and 2,500 2-PAM-reactivated sites/micron 2 of surface area of pre-and postjunctional membrane. This stacking density of DFP-binding sites per surface area of membrane ( probably in the overlying sheets of basal lamina) is very similar to that in the diaphragm and sternomastoid muscles.

scholarly journals ERRATUM

1972 ◽  
Vol 20 (11) ◽  
pp. 967-967
Keyword(s):  
Electron Microscope ◽  
Radiation Dose ◽  
Electron Microscope Autoradiography ◽  
Microscope Autoradiography

In the paper by Salpeter and Szabo entitled "Sensitivity in Electron Microscope Autoradiography. I. The Effect of Radiation Dose," which appeared in the June issue of the Journal (Vol. 20, pp. 425-434, 1972), the lines 28 and 29 of column 2 on page 427 should read, "2. In a second method, sections of tritiated methacrylate (10 mC/g or 400 µC/g) were used...."

Incorporation of Cholesterol into Peripheral Nerve Myelin

1972 ◽  
Vol 30 ◽  
pp. 334-335
Author(s):  
Frank A. Rawlins
Keyword(s):  
Electron Microscope ◽  
Sciatic Nerve ◽  
Electron Microscope Autoradiography ◽  
Myelin Sheaths ◽  
Microscope Autoradiography ◽  
Grain Distribution ◽  
Sciatic Nerves ◽  
Autoradiographic Analysis ◽  
Old Mice ◽  
Short Times

Several speculations exist as to the site of incorporation of preformed molecules into myelin. The possibility that an autoradiographic analysis of cholesterol-1,2-H3 incorporation at very short times after injection might shed some light in the solution of that problem led to the present experiment.Cholesterol-1,2-H3 was injected intraperitoneally into 24 tenday old mice. The animals were then sacrificed at 10,20,30,40,60,90,120 and 180 min after the injection and the sciatic nerves were processed for electron microscope autoradiography. To analyze the grain distribution in the autoradiograms of cross and longitudinal sections from each sciatic nerve myelin sheaths were subdivided into three compartments named: outer 1/3, middle 1/3 and inner 1/3 compartments.It was found that twenty min. after the injection of cholesterol -1.2-H3 (Figs. 1 and 2), 55% of the total number of grains (t.n.g) found in myelin were within the outer 1/3 compartment, 9% were within the middle 1/3 and 36% within the inner 1/3 compartment

scholarly journals Mpemba Effect- the Effect of Time

2021 ◽  
Author(s):  
Jianan Wang
Keyword(s):  
Gravitational Field ◽  
Surface Area ◽  
Time Effect ◽  
Light Quantum ◽  
Unit Surface Area ◽  
Heat Flows ◽  
Unit Surface ◽  
Average Wavelength ◽  
Nature Of Time ◽  
The Relationship

This paper draws the following conclusions on the nature of time by analyzing the relationship between time and speed, the relationship between time and gravitational field, the gravitational redshift of the photon, and the black-body radiation theorem: Time on an object is proportional to the amount of energy flowing out (or in) per unit time (observer’s time) per unit surface area of the object. When an object radiates energy outward: t'=μB(T) =μσT 4=μnhν/st Where t’ is the time on the object, μ is a constant, B(T) is the radiosity，the total energy radiated from the unit surface area of the object in unit time (observer’s time), σ is the Stefan-Boltzmann constant, T is the absolute temperature, n is the number of the photons radiated, ν is the average frequency of the photons radiated, s is the surface area of the object and t is the time on the observer. When the object radiates energy outward, the higher the energy density of the space (for example the stronger the gravitational field of the space), the smaller the radiosity B(T) of the object in the space, the longer the average wavelength of the light quantum emitted by the object, the slower the time on the object, the longer the life of the system. When the object radiates energy outward, the faster the object moves relative to the ether, the higher the energy density of the local space in which the object is located, the smaller the radiosity B(T) of the object, the longer the average wavelength of the light quantum radiated by the object, the slower the time on the object, and the longer the life of the system. When the object radiates energy outward, the higher the temperature of the object, the greater the object's radiosity B(T), the shorter the average wavelength of the light quantum radiated by the object, the faster the time on the object, and the shorter the life of the system. Applying the above conclusions about the nature of time, the author analyzes the Mpemba effect and the inverse Mpemba effect, and reaches the following conclusion: the Mpemba effect is the time effect produced when heat flows from objects into space, and the "inverse" Mpemba effect is the time effect produced when heat flows from space into objects.

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