The response of a mixed cell population in mouse testes to x-ray and HZE irradiation

1983 ◽  
Vol 41 ◽  
pp. 674-675
Author(s):  
D. E. Philpott ◽  
W. Sapp ◽  
C. Williams ◽  
J. Stevenson ◽  
S. Black ◽  
...  
Keyword(s):  
Radiation Effects ◽  
Dose Range ◽  
Life Cycles ◽  
X Rays ◽  
Mixed Cell ◽  
Particle Radiation ◽  
Thin Sections ◽  
Straight Line ◽  
Mixed Cell Population ◽  
Standard Manner

The testes sperraatogonial population differentiates from a stem cell (As) which, via a series of mitotic divisions, gives rise to spermatocytes. The spermatocytes undergo reductional meiotic divisions and mature into sperm. Short cellular life cycles make the testes an excellent tissue for quantitative studies of radiation effects.Brown B6D2F1 mice, aged 14 weeks, were exposed to Helium particle radiation (227 MeV) in the Berkeley 184 inch synchocyclotron and to x rays at 225 KvP and 15 mA. Doses ranged from 1 to 100 rads. Tissues were fixed in Triple Fix and embedded. Two-micron sections were stained with Toluidine Blue, and ultra-thin sections were stained in the standard manner for electron microscopy. All studies were done on the tissues 72 hrs after irradiation.Our previous work, on cell survival after graded doses of radiation, has shown a steeper slope (more sensitive response) in the low dose range below 20 rads. By convention, the resulting points were plotted by linear regression resulting in a "best fit" straight line.

scholarly journals Genomic Profiling of a Human Leukemic Monocytic Cell-Line (THP-1) Exposed to Alpha Particle Radiation

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Vinita Chauhan ◽  
Matthew Howland
Keyword(s):  
Gene Expression ◽  
Radiation Effects ◽  
Assessment Tool ◽  
Late Onset ◽  
Dose Range ◽  
Biological Assessment ◽  
Global Changes ◽  
Monocytic Cell ◽  
Particle Radiation ◽  
Monocytic Cell Line

This study examined alpha (α-) particle radiation effects on global changes in gene expression in human leukemic monocytic cells (THP-1) for the purposes of mining for candidate biomarkers that could be used for the development of a biological assessment tool. THP-1 cells were exposed toα-particle radiation at a dose range of 0 to 1.5 Gy. Twenty-four hours and three days after exposure gene expression was monitored using microarray technology. A total of 16 genes were dose responsive and classified as early onset due to their expression 24 h after exposure. Forty-eight transcripts were dose responsive and classified as late-onset as they were expressed 72 h after exposure. Among these genes, 6 genes were time and dose responsive and validated further using alternate technology. These transcripts were upregulated and associated with biological processes related to immune function, organelle stability and cell signalling/communication. This panel of genes merits further validation to determine if they are strong candidate biomarkers indicative ofα-particle exposure.

Phosphors as Sensors for Radiation-Induced Displacement Damage

2012 ◽  
Vol 1471 ◽  
Author(s):  
S. L. Gollub ◽  
R. R. Harl ◽  
S. L. Weeden-Wright ◽  
B. R. Rogers ◽  
D. G. Walker
Keyword(s):  
Radiation Effects ◽  
Spectral Signature ◽  
X Rays ◽  
Displacement Damage ◽  
Particle Radiation ◽  
Before And After ◽  
Radiation Induced ◽  
Significant Change ◽  
Alpha Irradiation ◽  
Rule Out

AbstractThe radiation-induced displacement damage in yttrium borate (YBO3) is studied under X-ray, proton, and alpha irradiation. The photoluminescence (PL) was tested before and after irradiation to determine whether damage occurred and whether it could be queried by examining the PL spectrum. Two different dopants (cerium and europium) were used to activate the phosphor because each provides not only a different spectral signature but also a different mechanism for altering the spectrum between the pre- and post-PL measurements. X-rays, being primarily ionizing radiation, did not show any significant change between the pre and post measurements. We expected protons and alphas to damage the crystal structure, evidence of which could be seen in the change in the spectra before and after irradiation. However, we found no change under alpha exposure (3.6 × 1010 particles/cm2) and a significant change after proton exposure (5 × 1015 particles/cm2). While the material appears to be sensitive to protons, we cannot rule out its sensitivity to alphas because the alpha fluence may be too low to show an effect. This result provides strong indication that our materials are being damaged by particle radiation and that the radiation effects can be quantified.

Structural preservation and absolute contrast of catalase crystal sections prepared with tannic acid

1983 ◽  
Vol 41 ◽  
pp. 448-449
Author(s):  
C.W. Akey ◽  
M. Szalay ◽  
S.J. Edelstein
Keyword(s):  
Tannic Acid ◽  
Beef Heart ◽  
X Rays ◽  
Screw Axis ◽  
General Applicability ◽  
Thin Sections ◽  
Beef Liver ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
Structural Preservation

Three methods of obtaining 20 Å resolution in sectioned protein crystals have recently been described. They include tannic acid fixation, low temperature embedding and grid sectioning. To be useful for 3-dimensional reconstruction thin sections must possess suitable resolution, structural fidelity and a known contrast. Tannic acid fixation appears to satisfy the above criteria based on studies of crystals of Pseudomonas cytochrome oxidase, orthorhombic beef liver catalase and beef heart F1-ATPase. In order to develop methods with general applicability, we have concentrated our efforts on a trigonal modification of catalase which routinely demonstrated a resolution of 40 Å. The catalase system is particularly useful since a comparison with the structure recently solved with x-rays will permit evaluation of the accuracy of 3-D reconstructions of sectioned crystals.Initially, we re-evaluated the packing of trigonal catalase crystals studied by Longley. Images of the (001) plane are of particular interest since they give a projection down the 31-screw axis in space group P3121. Images obtained by the method of Longley or by tannic acid fixation are negatively contrasted since control experiments with orthorhombic catalase plates yield negatively stained specimens with conditions used for the larger trigonal crystals.

Studies of metaphase chromosomes in the scanning transmission x-ray microscope: Image fidelity, radiation damage and specimen preparation

1992 ◽  
Vol 50 (2) ◽  
pp. 1038-1039
Author(s):  
Shawn Williams ◽  
Xiaodong Zhang ◽  
Susan Lamm ◽  
Jack Van’t Hof
Keyword(s):  
Visible Light ◽  
Radiation Damage ◽  
Cross Section ◽  
Imaging Techniques ◽  
Dose Range ◽  
Specimen Preparation ◽  
X Rays ◽  
Metaphase Chromosomes ◽  
X Ray ◽  
Scanning Transmission

The Scanning Transmission X-ray Microscope (STXM) is well suited for investigating metaphase chromosome structure. The absorption cross-section of soft x-rays having energies between the carbon and oxygen K edges (284 - 531 eV) is 6 - 9.5 times greater for organic specimens than for water, which permits one to examine unstained, wet biological specimens with resolution superior to that attainable using visible light. The attenuation length of the x-rays is suitable for imaging micron thick specimens without sectioning. This large difference in cross-section yields good specimen contrast, so that fewer soft x-rays than electrons are required to image wet biological specimens at a given resolution. But most imaging techniques delivering better resolution than visible light produce radiation damage. Soft x-rays are known to be very effective in damaging biological specimens. The STXM is constructed to minimize specimen dose, but it is important to measure the actual damage induced as a function of dose in order to determine the dose range within which radiation damage does not compromise image quality.

scholarly journals Radiation effects on shock propagation in Al target relevant to equation of state measurements

2007 ◽  
Vol 25 (1) ◽  
pp. 23-30 ◽  
Author(s):  
T. DESAI ◽  
R. DEZULIAN ◽  
D. BATANI
Keyword(s):  
Equation Of State ◽  
Reference Material ◽  
Radiation Effects ◽  
Laser Energy ◽  
Strong Shock ◽  
Shock Propagation ◽  
Laser Irradiance ◽  
X Rays ◽  
High Laser ◽  
High Intensity Laser

We present one-dimensional simulations performed using the multi group radiation hydro code MULTI with the goal of analyzing the target preheating effect under conditions similar to those of recent experiments aimed at studying the Equation of State (EOS) of various materials. In such experiments, aluminum is often used as reference material; therefore its behavior under strong shock compression and high-intensity laser irradiation (1013–1014 W/cm2) should be studied in detail. Our results reveal that at high laser irradiance, the laser energy available to induce shock pressure is reduced due to high X-rays generation. Simultaneously X-rays preheat the bulk of the reference material causing significant heating prior to shock propagation. Such effects induce deviations in shock propagation with respect to cold aluminum.

In Situ Testing and X Rays Radiation Effects of Pt/Bi3.15Nd0.85Ti3O12/Pt Ferroelectric Capacitors

2013 ◽  
Vol 712-715 ◽  
pp. 293-297
Author(s):  
Li Li
Keyword(s):  
Radiation Effects ◽  
Hysteresis Loops ◽  
Electrical Performance ◽  
Hysteresis Curve ◽  
X Rays ◽  
Shanghai Synchrotron Radiation Facility ◽  
X Ray ◽  
In The Beginning ◽  
Ferroelectric Capacitors

Pt/Bi3.15Nd0.85Ti3O12(BNT)/Pt ferroelectric capacitors were monitored using in situ X-ray irradiation with 10 keV at BL14B1 beamline (Shanghai Synchrotron Radiation Facility). BL14B1 combined with a ferroelectric analyzer enabled measurements in situ of electrical performance. The hysteresis curve (PE) of distortion depended on the polarization during irradiation, but the diffracted intensities of the (117) peak did not change in the beginning. ThePEcurve had a negligible change from 2.09×109Gy to 4.45×109Gy. Finally, bothPrandPr+very rapidly increased, but the intensities of (117) decreased. The hysteresis loops were remarkably deformed at the maximum total dose of 4.87×109Gy.

scholarly journals Quantitation of mast cell heparin by flow cytofluorometry.

1976 ◽  
Vol 24 (12) ◽  
pp. 1231-1238 ◽  
Author(s):  
L Enerbäck ◽  
G Berlin ◽  
I Svensson ◽  
I Rundquist
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Mixed Cell ◽  
Flow Cytofluorometry ◽  
Frequency Distributions ◽  
Cell Counts ◽  
Mixed Cell Population ◽  
Number Of Cells ◽  
Excellent Reproducibility

Mast cells can be automatically identified in a mixed cell population by flow cytofluorometry after Berberine sulphate staining. Volume specific counts of the total number of cells and number of mast cells, as well as frequency distributions of fluorescence intensities of mast cells, based on a large number of cells, can be rapidly obtained. Results obtained by microscope fluorometry of cells identified by phase contrast microscopy showviously published results it may be inferred that the fluorescence intensity of individual mast cells is proportional to mast cell heparin content. The automated cell counts correlated very well with manual hemocytometer counts. Both cell counts and the determination of mean mast cell fluorescence showed excellent reproducibility.

scholarly journals Preparation of Thin Sections

1998 ◽  
Vol 6 (7) ◽  
pp. 8-9
Author(s):  
Ian Chaplin
Keyword(s):  
Chemical Composition ◽  
Thin Section ◽  
Microprobe Analysis ◽  
Rock Sample ◽  
Rock Type ◽  
X Rays ◽  
Thin Sections ◽  
Economical Method ◽  
Optical Examination ◽  
Composition Of Minerals

The optical examination of a rock sample in thin section is the quickest and most economical method for classifying rock type and determining which analytical route to follow.Thin sections for transmitted light are the most common, but there are also:Polished Thin Sections • Polished sections are used for classification and identification of minerals that cannot be determined in standard thin sections. They are also essential for microprobe analysis. Minute mineral grains are analyzed by bombarding them with a focused bean of electrons, which generate x-rays, characteristic of the elements within the grains. X-rays are identified and quantified to determine the chemical composition of minerals.

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