Eds Of Radioactive Particles By Self-Induced Fluorescence

1990 ◽  
Vol 48 (2) ◽  
pp. 238-239
Author(s):  
Gregory L. Finch ◽  
Richard G. Cuddihy
Keyword(s):  
Electron Beam Irradiation ◽  
Nuclear Reactor ◽  
X Rays ◽  
Reactor Accident ◽  
Internal Radiation ◽  
X Ray ◽  
External Sources ◽  
X Irradiation ◽  
Available Information ◽  
Individual Particles

The elemental composition of individual particles is commonly measured by using energydispersive spectroscopic microanalysis (EDS) of samples excited with electron beam irradiation. Similarly, several investigators have characterized particles by using external monochromatic X-irradiation rather than electrons. However, there is little available information describing measurements of particulate characteristic X rays produced not from external sources of radiation, but rather from internal radiation contained within the particle itself. Here, we describe the low-energy (< 20 KeV) characteristic X-ray spectra produced by internal radiation self-excitation of two general types of particulate samples; individual radioactive particles produced during the Chernobyl nuclear reactor accident and radioactive fused aluminosilicate particles (FAP). In addition, we compare these spectra with those generated by conventional EDS.Approximately thirty radioactive particle samples from the Chernobyl accident were on a sample of wood that was near the reactor when the accident occurred. Individual particles still on the wood were microdissected from the bulk matrix after bulk autoradiography.

Developmental effects of X-irradiation of early Drosophila embryos

Development ◽  
1977 ◽  
Vol 39 (1) ◽  
pp. 253-259
Author(s):  
M. Bownes ◽  
L. A. Sunnell
Keyword(s):  
Early Embryogenesis ◽  
X Rays ◽  
X Ray ◽  
Developmental Effects ◽  
Morphological Defects ◽  
X Irradiation ◽  
Drosophila Embryos ◽  
Adult Cells

Drosophila embryos were treated at specific stages during early embryogenesis with various doses of X-irradiation. The lethality at various times during development was established and pattern defects in the adults noted. It was observed that the most sensitive stages of embryogenesis to X-ray-induced lethality were also the stages where most morphological defects were found in the adults which emerged. This suggests that presumptive larval and adult cells are sensitive to X-rays at the same stages of embryogenesis.

scholarly journals STUDIES ON THE MECHANISM OF ACTION OF IONIZING RADIATIONS

1952 ◽  
Vol 35 (6) ◽  
pp. 865-871 ◽  
Author(s):  
E. S. Guzman Barron ◽  
S. Louise Seki
Keyword(s):  
Cell Division ◽  
Sperm Cells ◽  
X Rays ◽  
Thiol Compounds ◽  
X Ray ◽  
Arbacia Punctulata ◽  
Inhibiting Effect ◽  
Small Doses ◽  
X Irradiation ◽  
Ionizing Radiations

On x-irradiation of the eggs and sperm of Arbacia punctulata there was inhibition of respiration with relatively large doses, whereas there was an increase with small doses. The dose required to produce an increase of respiration depended on the degree of sensitivity of the cell to the effect of ionizing radiation. Sperm cells were more sensitive; then came fertilized eggs; unfertilized eggs were the least sensitive. The inhibiting effect of x-rays on cell division was observed even on irradiation with x-ray doses which produced an increase of respiration. These results are compared to similar effects produced by thiol reagents and are attributed to oxidation of the thiol compounds in the cell.

scholarly journals Safety and Functional Integrity of Continuous Glucose Monitoring Components After Simulated Radiologic Procedures

2020 ◽  
pp. 193229682092094 ◽  
Author(s):  
Christopher Thomas ◽  
John B. Welsh ◽  
Spencer Lu ◽  
J. Michael Gray
Keyword(s):  
Magnetic Fields ◽  
Continuous Glucose Monitoring ◽  
Glucose Monitoring ◽  
Data Integrity ◽  
X Rays ◽  
X Ray ◽  
X Irradiation ◽  
Induced Currents ◽  
Displacement Force ◽  
Magnetic Resonance Imaging Mri

Background: We investigated wearable components of the Dexcom G6 continuous glucose monitoring (CGM) System in simulated therapeutic and diagnostic radiologic procedures. Methods: G6 transmitters were loaded with simulated glucose data and attached to sensors. Sets of sensor/transmitter pairs were exposed to x-rays to simulate a radiotherapeutic procedure and to radiofrequency (RF) and magnetic fields to simulate diagnostic magnetic resonance imaging (MRI). The x-ray simulation provided a cumulative dose of 80 Gy. The MRI simulation used RF fields oscillating at 64 or 128 MHz and magnetic fields of 1.5 or 3 T. During the MRI simulation, displacement force, induced heating, and induced currents were measured. After the simulations, bench tests were used to assess data integrity on the transmitters and responsiveness of sensors to various concentrations of aqueous glucose. Results: Glucose concentrations reported by sensor/transmitter pairs after undergoing x-irradiation or a simulated MRI exam were similar to those from control (unexposed) devices. During the 3 T MRI simulation, the devices experienced a displacement force of 306 g, which was insufficient to dislodge the sensor/transmitter from the substrate, RF-induced heating of <2°C, and an induced current of <16 pA. Data stored on the transmitters prior to the MRI simulation remained intact. Conclusion: Wearable components of the G6 CGM System retain basic functionality and data integrity after exposure to simulated therapeutic and diagnostic radiologic procedures. The devices are unlikely to be affected by x-irradiation used in typical imaging studies. Simulated MRI procedures create displacement force, minimal heating, and current in sensor/transmitter pairs.

Resistance to whole-body X-irradiation in rats made tolerant to bacterial endotoxins

1959 ◽  
Vol 197 (6) ◽  
pp. 1364-1370 ◽  
Author(s):  
B. W. Zweifach ◽  
E. Kivy-Rosenberg ◽  
Arnold L. Nagler
Keyword(s):  
Blood Platelet ◽  
Reticuloendothelial System ◽  
Whole Body ◽  
X Rays ◽  
Effective Protection ◽  
X Ray ◽  
E Coli ◽  
Bacterial Endotoxins ◽  
X Irradiation ◽  
Reticulo Endothelial System

Rats were treated with three conditioning agents (bacterial endotoxins, zymosan and compound 48/80) known to produce tolerance to other forms of stress, as a means of determining the importance of the reticulo-endothelial system in the response to WBR. Effective protection was provided by tolerance induced by lipopolysaccharide extracts of E. coli bacteria. Some protection was also afforded by conditioning with 48/80 for several days. These agents were active only when administered before exposure to x-rays. Treatment post x-ray broke down the induced resistance. Blood platelet levels remained high in conditioned animals exposed to WBR. It is suggested that a relationship exists between the priming or conditioning of the reticuloendothelial system and the maintenance of satisfactory blood platelet levels in adapted animals receiving WBR.

scholarly journals Effect of X-ray sterilisation on œstrus in the ferret

1932 ◽  
Vol 109 (764) ◽  
pp. 425-434 ◽  
Keyword(s):  
Guinea Pig ◽  
Species Difference ◽  
X Rays ◽  
Large Follicle ◽  
X Ray ◽  
Complete Obliteration ◽  
X Irradiation

Complete obliteration of the Graafian follicles in the mouse by exposure to X-rays does not suppress the œstrous changes in the uterus and vagina (Parkes, 1926-27; Brambell, Fielding and Parkes, 1927-28; Schugt, 1928; Geller, 1930). It is evident, therefore, that in this animal the actual elaboration of œstrin is not dependent upon the presence of the follicular system. Similar results have been reported on the rat (Ford and Drips, 1929). In the guinea-pig, on the contrary, Genther (1931) finds that the uterine and vaginal changes invariably cease after total obliteration of the follicles. Such of her irradiated animals as showed œstrus all possessed at least one large follicle. In view of the variation in mammalian ovaries, a species difference in the response to X-irradiation might well be expected; in order to investigate this point, experiments were begun two years ago on an animal with a type of ovary and cycle distinct from that of the mouse, i. e ., the ferret. The results are described below.

THE HYPOPHYSIAL CONTROL OF THE X-RAY STERILIZED OVARY

1958 ◽  
Vol 17 (1) ◽  
pp. 1-12 ◽  
Author(s):  
D. L. INGRAM ◽  
ANITA M. MANDL
Keyword(s):  
Stromal Cells ◽  
The Other ◽  
Vaginal Smear ◽  
X Rays ◽  
Adult Rats ◽  
X Ray ◽  
Uterine Involution ◽  
Other Hand ◽  
X Irradiation

SUMMARY Adult rats which had been previously sterilized by means of X-rays were hypophysectomized a fortnight after the onset of continuous vaginal cornification (which begins within 40 days of X-irradiation [Mandl & Zuckerman, 1956]). The animals, including non-irradiated hypophysectomized controls, were killed at periods of 5–70 days after hypophysectomy. Cornified cells disappeared from the vaginal smear of non-irradiated rats within 3, and of irradiated rats within 4 days after hypophysectomy. The ovaries involuted rapidly in both groups of animals. Stromal cells decreased in size and post-hypophysectomy 'deficiency cells' appeared. On the other hand, the rate of uterine involution was slower in the X-irradiated animals after hypophysectomy than in the non-irradiated hypophysectomized controls. This finding indicates that in the absence of the pituitary, the X-irradiated ovary can produce more oestrogen than a non-irradiated ovary, or that the oestrogen it produces is biologically more active. After treatment with gonadotrophin, the 'deficiency cells' in the ovaries of both groups of animals disappeared. The X-irradiated hypophysectomized animals responded to the gonadotrophin less vigorously (as judged by an increase in ovarian and uterine size) than did the hypophysectomized controls.

scholarly journals MUTANTS PRODUCED BY X-IRRADIATION OF SPORES OF CHAETOMIUM GLOBOSUM AND A COMPARISON WITH THOSE PRODUCED BY ULTRAVIOLET IRRADIATION

1949 ◽  
Vol 32 (6) ◽  
pp. 647-653 ◽  
Author(s):  
J. M. Ford ◽  
D. P. Kirwan
Keyword(s):  
Ultraviolet Irradiation ◽  
Wave Length ◽  
Fungal Spores ◽  
Chaetomium Globosum ◽  
Theoretical Curve ◽  
Striking Difference ◽  
X Rays ◽  
X Ray ◽  
Large Numbers ◽  
X Irradiation

1. Mutants produced by x-irradiation of fungal spores of Chaetomium globosum have been compared with those produced by ultraviolet irradiation. 2. The most striking difference between the mutants produced by x-irradiation and ultraviolet irradiation is the absence in x-ray experiments of the K mutant which is produced in large numbers at short ultraviolet wave lengths. 3. A comparison is made of the relation between x-ray dose and numbers of lethal mutants, and the relation between the short ultraviolet wave length 2804 dose and numbers of lethal mutants. Both are compared with theoretical curves for 1, 2, 5, and 8 quantum hits. 4. The production of lethal mutants by x-rays is shown to be consistent with the theoretical curve for five quantum hits on the sensitive spot of the spore, whereas the production of lethal mutants by the ultraviolet wave length 2804 Å.u. is consistent with two quantum hits.

Effects of X-rays on nerve-dependent (limb) and nerve-independent (jaw) regeneration in the adult newt, Notophthalmus viridescens

Development ◽  
1979 ◽  
Vol 53 (1) ◽  
pp. 315-325
Author(s):  
Richard L. Wertz ◽  
Donald J. Donaldson
Keyword(s):  
Histological Examination ◽  
Inhibitory Action ◽  
Notophthalmus Viridescens ◽  
X Rays ◽  
X Ray ◽  
Adult Newt ◽  
X Irradiation ◽  
Left Front ◽  
Newt Limb

The newt limb requires nerves for successful regeneration, but the jaw appears to be nerve independent. Among the current hypotheses for the regeneration-inhibitory action of X-rays is one proposing inactivation of nerves as the main cause. We decided to test this hypothesis by comparing the irradiation levels necessary for inhibition of limb and jaw regeneration. Jaws and left front limbs were exposed locally to doses of ionizing X-irradiation ranging from 250 to 2000 R at least 6 weeks prior to amputation of the jaw and both front limbs. After 90 days post-amputation all surviving animals were examined grossly for signs of regeneration. In addition, some of the controls and most of those receiving 250, 500 and 1000 R were processed for histological examination. All unirradiated limbs and jaws supported regeneration. Those exposed to 250 R also regenerated, but a third of the jaws were hypomorphic. At 500 R and above, neither jaws nor limbs regenerated. Since both systems were affected by similar doses of X-rays, it appears that nerves are not the primary X-ray target in adult newts.

Determination of residual stresses around blisters in Zr-2.5%Nb pressure tubes

2009 ◽  
Vol 24 (S1) ◽  
pp. S72-S76 ◽  
Author(s):  
Javier R. Santisteban ◽  
Axel Steuwer ◽  
Gladys Domizzi ◽  
Matthew J. Peel
Keyword(s):  
Nuclear Reactor ◽  
Axial Direction ◽  
High Energy ◽  
European Synchrotron Radiation Facility ◽  
Large Strains ◽  
Cold Spot ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compressive Stresses

We have used synchrotron X-ray diffraction experiments to measure the strain field introduced by a hydride blister grown on a section of a pressure tube from a CANDU nuclear reactor. After charging the tube section with a homogeneous hydrogen concentration of 300 wt ppm, the blister was produced by creating a small cold spot on its surface (∼200 °C), while the bulk was kept at a temperature of 338 °C over a period of 1008 h. The blister studied here is ellipsoidal in shape, with its long axis along the tube axial direction. The experiments were performed on the wiggler beam line ID15 at the European Synchrotron Radiation Facility (ESRF) using a polychromatic beam of high-energy X-rays (60 to 300 keV). Unlike conventional X-ray diffraction, in this mode the scattering angle is fixed and the diffracted beam is discriminated on the basis of the photon energy. The results show that the blister is composed by two crystallographic phases (δ-ZrH and α-Zr), with volume fractions varying with position. The maximum stresses appear at the blister-matrix interfaces. Near the tube outer surface, we found large compressive stresses of (−450±90) MPa along the blister long axis, and tensile stresses (+320±90) MPa along the tube hoop direction. The main uncertainty in these stresses results from the uncertainty in the elastic constants of the hydride phase. Large strains and broad peaks were observed for this phase, which were explained by a rather low Young’s modulus (35 GPa) for the hydride. The results are compared with finite element simulations found in the literature.

Use of pattern recognition tools for classifying particles into homogeneous groups

1992 ◽  
Vol 50 (2) ◽  
pp. 1484-1485
Author(s):  
Philip K. Hopke
Keyword(s):  
General Procedure ◽  
Photon Counting ◽  
X Rays ◽  
Homogeneous Groups ◽  
X Ray ◽  
Balance Analysis ◽  
Data Screening ◽  
Individual Particles

Computer-controlled scanning electron microscopy (CCSEM) permits the characterization of size, shape, and composition of individual particles and thus provides a rich source of data to identify the origin of ambient airborne particles. The problem is how to make best use of this information. The general procedure has been to assign each particle to a class of similar particles based on its x-ray fluorescence spectrum. The initial efforts developed the class characteristics and classification rules in an empirical fashion. Recent studies have suggested that greater specificity and precision in the subsequent class balance analysis can be obtained if particle classes are more homogeneous.Data screening and transformation are the initial steps in the analysis procedure. Noise reduction is the first step in analyzing the CCSEM data. Determination of elemental chemistry for individual particles is accomplished by collection of characteristic X-rays. The X-ray fluorescence peaks are obtained as a result of a photon counting process having a Poissonian distribution.

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