Technical Attenuation Length Measurement of Plastic Scintillator Strips for the Total-Body J-PET Scanner

2020 ◽  
Vol 67 (10) ◽  
pp. 2286-2289
Author(s):  
ukasz Kaplon
Author(s):  
S. Phyllis Steamer ◽  
Rosemarie L. Devine

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.


Author(s):  
Vivian V. Yang ◽  
S. Phyllis Stearner

The heart is generally considered a radioresistant organ, and has received relatively little study after total-body irradiation with doses below the acutely lethal range. Some late damage in the irradiated heart has been described at the light microscopic level. However, since the dimensions of many important structures of the blood vessel wall are submicroscopic, investigators have turned to the electron microscope for adequate visualization of histopathological changes. Our studies are designed to evaluate ultrastructural changes in the mouse heart, particularly in the capillaries and muscle fibers, for 18 months after total-body exposure, and to compare the effects of 240 rad fission neutrons and 788 rad 60Co γ-rays.Three animals from each irradiated group and three control mice were sacrificed by ether inhalation at 4 days, and at 1, 3, 6, 12, and 18 months after irradiation. The thorax was opened and the heart was fixed briefly in situwith Karnofsky's fixative.


1974 ◽  
Vol 126 (2) ◽  
pp. 243-248
Author(s):  
A WAKABAYASHI ◽  
T KUBO ◽  
K CHARNEY ◽  
Y NAKAMURA ◽  
J CONNOLLY

2008 ◽  
Vol 39 (4) ◽  
pp. 20
Author(s):  
SHARON WORCESTER
Keyword(s):  

2003 ◽  
Vol 31 (2) ◽  
pp. 209-213 ◽  
Author(s):  
Carel F. Hollander ◽  
Chris Zurcher ◽  
Johan J. Broerse

2014 ◽  
Vol 84 (Supplement 1) ◽  
pp. 52-59 ◽  
Author(s):  
Sherry A. Tanumihardjo ◽  
Anura V. Kurpad ◽  
Janet R. Hunt

The current use of serum retinol concentrations as a measurement of subclinical vitamin A deficiency is unsatisfactory for many reasons. The best technique available for vitamin A status assessment in humans is the measurement of total body pool size. Pool size is measured by the administration of retinol labelled with stable isotopes of carbon or hydrogen that are safe for human subjects, with subsequent measurement of the dilution of the labelled retinol within the body pool. However, the isotope techniques are time-consuming, technically challenging, and relatively expensive. There is also a need to assess different types of tracers and doses, and to establish clear guidelines for the use and interpretation of this method in different populations. Field-friendly improvements are desirable to encourage the application of this technique in developing countries where the need is greatest for monitoring the risk of vitamin A deficiency, the effectiveness of public health interventions, and the potential of hypervitaminosis due to combined supplement and fortification programs. These techniques should be applied to validate other less technical methods of assessing vitamin A deficiency. Another area of public health relevance for this technique is to understand the bioconversion of β-carotene to vitamin A, and its relation to existing vitamin A status, for future dietary diversification programs.


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