A Study of Some Metabolic Requirements for Repair of Sublethal Irradiation Damage

Radiology ◽  
1969 ◽  
Vol 93 (4) ◽  
pp. 895-899 ◽  
Author(s):  
Regina Roux Ashby ◽  
Frederick J. Bonte ◽  
James A. Belli
Keyword(s):  
Irradiation Damage ◽  
Sublethal Irradiation

Mitigation of Irradiation Induced Potentially Lethal Damage (PLD) in Hematopoietic Cells by Mitochondrial Localized GS-Nitroxide, JP4-039

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4725-4725
Author(s):  
Kanika Gupta ◽  
Michael W Epperly ◽  
Darcy Franicola ◽  
Xichen Zhang ◽  
Joshua G Pierce ◽  
...  
Keyword(s):  
Cell Growth ◽  
Cell Viability ◽  
Cultured Cells ◽  
Hematopoietic Cells ◽  
Irradiation Damage ◽  
Cell Counts ◽  
Significant Change ◽  
Total Body ◽  
Sublethal Irradiation ◽  
Time Point

Abstract PLD is an ionizing irradiation pathway believed to apply to quiescent hematopoietic cells in the marrow microenvironment. To determine if the mitochondrial targeted JP4-039 which has been shown to mitigate sublethal irradiation damage (SLD) in non-quiescent clonagenic cells protected cells from PLD, 32D cl 3 hematopoietic cells were irradiated in three sets of cultures to doses ranging from 0 to 8 Gy. To one group of cells, to measure SLD mitigation effects, JP4-039 (10 μM) was added immediately, then cells plated in methycellulose, and incubated at 37°C for seven days at which time colonies of greater than 50 cells counted. The second set of irradiated cells was grown in flasks in 10 ml of liquid media. The third set was tested for PLD effects and cells were centrifuged and maintained in pellets in 1 ml of media (PLD conditions preventing cell growth or division) and these latter two sets were kept at 37°C. After 24, 48 or 72 hrs irradiation, subsets of each were removed, viability and cell counts were determined and JP4-039 was then added to subgroups of cultured cells at each time point, cells re-suspended in methycellulose, and incubated at 37°C for seven days at which time colonies of greater than 50 cells counted. Viability of cells in non-irradiated pellets decreased from 24 to 72 hours from 60.3 ± 2.7% to 37.3 ± 2.3% (p = 0.0030), while after 8 Gy the cell viability was 57. 3 ± 0.3% at 24 hr and 25.7 ± 6.1% at 72 hr (p = 0.0065). There was no significant decrease in percent viability at 24 hrs of non-irradiated or 8 Gy irradiated cells (60.3 ± 2.7% and 57.3 ± 0.3%, respectively) or at 72 hr (37.3 ± 2.3% and 25.7 ± 6.1%, respectively). In contrast, non-irradiated cells re-suspended in flasks grew and thus viability increased from 77.0 ± 4.0% at 24 hr to 96.7 ± 0.3% at 72 hr (p = 0.0080). Cell viability after 8 Gy of surviving irradiated cells grown in flasks was not significantly changed from 64.0 ± 10.6% at 24 hr to 49.3 + 3.2% at 72 hr. There was no significant change in cell viability in flasks at 24 hrs of non-irradiated or 8 Gy irradiated cells (77 ± 4.0% and 64.0 ± 10.6%, respectively). Cell viability was significantly decreased at 72 hr in non-irradiated cell flasks of 96.7 ± 0.3% compared to 8 Gy irradiated flasks with a viability of 49.3 ± 3.2% (p = 0.0001). Cells maintained in pellets showed there was no cell growth between 24 to 72 hours while those maintained in flasks did significantly grow for non-irradiated cells from 6.3 ± 0.2 × 105 cells at 24 hr to 85.3 ± 6.8 × 105 cells at 72 hr (p = 0.0003). For 8 Gy irradiated cells grown in flasks, there was no significant change in the number of cells between 24 and 72 hr (4.9 ± 0.9 × 105 and 4.9 ± 1.2 × 105, respectively). Thus, PLD conditions were established in pellets. Irradiation survival curves showed a JP4-039 mediated PLD radiation resistance when cells were incubated in JP4-039 at 24 hr or 72 hr after irradiation by increase in the Do. At 24 hr, the Do for pelleted cells incubated in JP4-039 was 1.92 ± 0.01 Gy compared to pelleted irradiated control 32D cl 3 cells, 1.36 ± 0.02 Gy (p = 0.0014). At 24 hrs, cells grown in flasks and incubated in JP4-039 had a Do of 1.70 ± 0.02 Gy compared to 1.40 ± 0.05 Gy for irradiated control 32D cl 3 cells (p = 0.0261). By 72 hrs after irradiation, the Do for pelleted cells was increased to 1.97 ± 0.06 Gy by adding JP4-039 compared to the pelleted irradiated control 32D cl 3 cells with a Do of 1.51 ± 0.04 Gy (p = 0.0218). In cells grown in flasks for 72 hr before the addition of JP4-039 the Do was 2.01 ± 0.02 Gy compared to irradiated controls which had a Do of 1.62 ± 0.07 Gy (p = 0.0346). Therefore, JP4-039 displays a clear potential to mitigate irradiation induced PLD damage. These data correlate with significant mitigation of the hematopoietic syndrome by JP4-039 in total body irradiated C57BL/6NHsd mice.

Development of a conical anode Fe-gun for low voltage SEM

1988 ◽  
Vol 46 ◽  
pp. 978-979
Author(s):  
T. Miyokawa ◽  
S. Norioka ◽  
S. Goto
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Low Voltage ◽  
Irradiation Damage ◽  
Cold Cathode ◽  
Virtual Source ◽  
Source Position ◽  
Electrostatic Lens ◽  
Electrostatic Lenses ◽  
Wide Range

Field emission SEMs (FE-SEMs) are becoming popular due to their high resolution needs. In the field of semiconductor product, it is demanded to use the low accelerating voltage FE-SEM to avoid the electron irradiation damage and the electron charging up on samples. However the accelerating voltage of usual SEM with FE-gun is limited until 1 kV, which is not enough small for the present demands, because the virtual source goes far from the tip in lower accelerating voltages. This virtual source position depends on the shape of the electrostatic lens. So, we investigated several types of electrostatic lenses to be applicable to the lower accelerating voltage. In the result, it is found a field emission gun with a conical anode is effectively applied for a wide range of low accelerating voltages.A field emission gun usually consists of a field emission tip (cold cathode) and the Butler type electrostatic lens.

In situ irradiation effects studies in medium- and high-voltage TEM

1995 ◽  
Vol 53 ◽  
pp. 234-235
Author(s):  
Charles W. Allen
Keyword(s):  
Cross Section ◽  
Particle Flux ◽  
Threshold Value ◽  
High Energy ◽  
Irradiation Damage ◽  
Defect Complexes ◽  
Lattice Position ◽  
Electrons And Ions ◽  
The Masses

With respect to structural consequences within a material, energetic electrons, above a threshold value of energy characteristic of a particular material, produce vacancy-interstial pairs (Frenkel pairs) by displacement of individual atoms, as illustrated for several materials in Table 1. Ion projectiles produce cascades of Frenkel pairs. Such displacement cascades result from high energy primary knock-on atoms which produce many secondary defects. These defects rearrange to form a variety of defect complexes on the time scale of tens of picoseconds following the primary displacement. A convenient measure of the extent of irradiation damage, both for electrons and ions, is the number of displacements per atom (dpa). 1 dpa means, on average, each atom in the irradiated region of material has been displaced once from its original lattice position. Displacement rate (dpa/s) is proportional to particle flux (cm-2s-1), the proportionality factor being the “displacement cross-section” σD (cm2). The cross-section σD depends mainly on the masses of target and projectile and on the kinetic energy of the projectile particle.

High-Resolution Cryo-Electron Microscopy of Biological Macromolecules

1990 ◽  
Vol 48 (1) ◽  
pp. 126-127
Author(s):  
Yoshinori Fujiyoshi
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Diffraction Pattern ◽  
Superfluid Helium ◽  
Copper Phthalocyanine ◽  
Optical Diffraction ◽  
Irradiation Damage ◽  
Biological Macromolecules ◽  
Cross Sectional ◽  
Instrumental Resolution

The resolution of direct images of biological macromolecules is normally restricted to far less than 0.3 nm. This is not due instrumental resolution, but irradiation damage. The damage to biological macromolecules may expect to be reduced when they are cooled to a very low temperature. We started to develop a new cryo-stage for a high resolution electron microscopy in 1983, and successfully constructed a superfluid helium stage for a 400 kV microscope by 1986, whereby chlorinated copper-phthalocyanine could be photographed to a resolution of 0.26 nm at a stage temperature of 1.5 K. We are continuing to develop the cryo-microscope and have developed a cryo-microscope equipped with a superfluid helium stage and new cryo-transfer device.The New cryo-microscope achieves not only improved resolution but also increased operational ease. The construction of the new super-fluid helium stage is shown in Fig. 1, where the cross sectional structure is shown parallel to an electron beam path. The capacities of LN2 tank, LHe tank and the pot are 1400 ml, 1200 ml and 3 ml, respectively. Their surfaces are placed with gold to minimize thermal radiation. Consumption rates of liquid nitrogen and liquid helium are 170 ml/hour and 140 ml/hour, respectively. The working time of this stage is more than 7 hours starting from full LN2 and LHe tanks. Instrumental resolution of our cryo-stage cooled to 4.2 K was confirmed to be 0.20 nm by an optical diffraction pattern from the image of a chlorinated copper-phthalocyanine crystal. The image and the optical diffraction pattern are shown in Fig. 2 a, b, respectively.

A Study of Electron Beam Irradiation Influence on Device Contact Junction Characteristics of Advanced DRAM Using Atomic Force Probing

2013 ◽  
Author(s):  
Wei-Chih Wang ◽  
Jian-Shing Luo
Keyword(s):  
Electron Beam ◽  
Electron Beam Irradiation ◽  
Forward Bias ◽  
Irradiation Damage ◽  
Beam Irradiation ◽  
Excess Current ◽  
Atomic Force ◽  
Order Of Magnitude ◽  
Voltage Contrast ◽  
Acceleration Voltage

Abstract In this paper, we revealed p+/n-well and n+/p-well junction characteristic changes caused by electron beam (EB) irradiation. Most importantly, we found a device contact side junction characteristic is relatively sensitive to EB irradiation than its whole device characteristic; an order of magnitude excess current appears at low forward bias region after 1kV EB acceleration voltage irradiation (Vacc). Furthermore, these changes were well interpreted by our Monte Carlo simulation results, the Shockley-Read Hall (SRH) model and the Generation-Recombination (G-R) center trap theory. In addition, four essential examining items were suggested and proposed for EB irradiation damage origins investigation and evaluation. Finally, by taking advantage of the excess current phenomenon, a scanning electron microscope (SEM) passive voltage contrast (PVC) fault localization application at n-FET region was also demonstrated.

scholarly journals Carbon ion radiotherapy for recurrent calf myxoid liposarcoma: a case report

2021 ◽  
Vol 49 (4) ◽  
pp. 030006052110097
Author(s):  
Xiaojun Li ◽  
Yanshan Zhang ◽  
Yancheng Ye ◽  
Ying Qi ◽  
Chunlan Feng ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Soft Tissue Sarcomas ◽  
Myxoid Liposarcoma ◽  
Ion Beams ◽  
Carbon Ion Radiotherapy ◽  
Irradiation Damage ◽  
Radiation Dermatitis ◽  
Complete Disappearance ◽  
Carbon Ion ◽  
The Right

Liposarcoma (LPS) is the most common soft tissue sarcoma. Myxoid LPS (MLPS) is the second most common subtype of LPS and accounts for 25% to 50% of all LPSs. Like most other soft tissue sarcomas, the mainstay of treatment for LPS is inevitably surgery. Multidisciplinary approaches, including surgery, chemotherapy, and radiotherapy, have been successful in the treatment of LPS during the last three decades. Even so, recurrence of LPS remains challenging. Carbon ion beams produce increased energy deposition at the end of their range to form a Bragg peak while minimizing irradiation damage to surrounding tissues, which facilitates more precise dosage and localization than that achieved with photon beams. Furthermore, carbon ion beams have high relative biologic effectiveness. We herein describe a patient who developed recurrent MLPS in the right calf after two surgeries and underwent carbon ion radiotherapy (CIRT), achieving complete disappearance of the tumor. The patient developed Grade 1 radiation dermatitis 30 days after CIRT, but no other acute toxicities were observed. The tumor had completely disappeared by 120 days after CIRT, and the patient remained disease-free for 27 months after CIRT. The CARE guidelines were followed in the reporting of this case.

scholarly journals High-Entropy Alloys for Advanced Nuclear Applications

Entropy ◽  
2021 ◽  
Vol 23 (1) ◽  
pp. 98
Author(s):  
Ed J. Pickering ◽  
Alexander W. Carruthers ◽  
Paul J. Barron ◽  
Simon C. Middleburgh ◽  
David E.J. Armstrong ◽  
...  
Keyword(s):  
Austenitic Steels ◽  
Irradiation Damage ◽  
High Entropy Alloys ◽  
Damage Resistance ◽  
High Entropy ◽  
Engineering Alloys ◽  
Sluggish Diffusion ◽  
Work Done ◽  
Current Engineering ◽  
Nuclear Applications

The expanded compositional freedom afforded by high-entropy alloys (HEAs) represents a unique opportunity for the design of alloys for advanced nuclear applications, in particular for applications where current engineering alloys fall short. This review assesses the work done to date in the field of HEAs for nuclear applications, provides critical insight into the conclusions drawn, and highlights possibilities and challenges for future study. It is found that our understanding of the irradiation responses of HEAs remains in its infancy, and much work is needed in order for our knowledge of any single HEA system to match our understanding of conventional alloys such as austenitic steels. A number of studies have suggested that HEAs possess `special’ irradiation damage resistance, although some of the proposed mechanisms, such as those based on sluggish diffusion and lattice distortion, remain somewhat unconvincing (certainly in terms of being universally applicable to all HEAs). Nevertheless, there may be some mechanisms and effects that are uniquely different in HEAs when compared to more conventional alloys, such as the effect that their poor thermal conductivities have on the displacement cascade. Furthermore, the opportunity to tune the compositions of HEAs over a large range to optimise particular irradiation responses could be very powerful, even if the design process remains challenging.

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