Imaging and range estimations of prompt X-rays using YAP(Ce) camera during particle-ion irradiation to phantoms with air cavities

2021 ◽  
Vol 16 (08) ◽  
pp. P08064
Author(s):  
M. Kitano ◽  
S. Yamamoto ◽  
T. Yabe ◽  
T. Akagi ◽  
T. Toshito ◽  
...  
Keyword(s):  
Ion Irradiation ◽  
X Rays ◽  
Air Cavities

Build-up effects at air cavities for 25 MV X-rays

1978 ◽  
Vol 4 ◽  
pp. 206
Author(s):  
Fred G. Abrath ◽  
James A. Purdy ◽  
P. Steward
Keyword(s):  
X Rays ◽  
Air Cavities

Work Function Modulation of Few-Layer Graphene by Swift Heavy Ion Irradiation

2021 ◽  
Vol 21 (11) ◽  
pp. 5603-5610
Author(s):  
P. K. Kasana ◽  
Jyoti Shakya ◽  
Tanuja Mohanty
Keyword(s):  
Surface Roughness ◽  
Work Function ◽  
Defect Density ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
Diffraction Measurement ◽  
X Rays ◽  
Swift Heavy Ion Irradiation ◽  
Heavy Ion Irradiation ◽  
Swift Heavy Ion

Here, we report the structural and electronic modification induced in chemical vapor deposited graphene by using swift heavy ions (70 MeV Ni6+).Raman spectroscopy was used to quantify the irradiation-induced modification in vibrational properties. The increase in defect density with fluence causes an increase in the intensity ratio of its characteristic Raman D and G band. The increase in defect density also results in a decrease in crystallite size. The changes in the crystal structure are observed from X-rays diffraction measurement. Swift heavy ion irradiation induced defect, modified the surface roughness and surface potential of graphene thin film as measured from atomic force microscopy and scanning Kelvin probe microscopy respectively. The increase in the work function, surface roughness as well as defect concentration with fluence, indicate the possibility of linear correlation between them. Presence of defects in graphene sheets strongly affects surface electronic and optical properties of the material that can be used to tailor the optoelectronics device performance.

Sensitivity improvement of YAP(Ce) cameras for imaging of secondary electron bremsstrahlung x-rays emitted during carbon-ion irradiation: problem and solution

2020 ◽  
Vol 65 (10) ◽  
pp. 105008 ◽  
Author(s):  
Seiichi Yamamoto ◽  
Mitsutaka Yamaguchi ◽  
Takashi Akagi ◽  
Maki Kitano ◽  
Naoki Kawachi
Keyword(s):  
Secondary Electron ◽  
Ion Irradiation ◽  
X Rays ◽  
Carbon Ion ◽  
Electron Bremsstrahlung ◽  
Sensitivity Improvement

scholarly journals ROS Production and Distribution: A New Paradigm to Explain the Differential Effects of X-ray and Carbon Ion Irradiation on Cancer Stem Cell Migration and Invasion

Cancers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 468 ◽  
Author(s):  
Anne-Sophie Wozny ◽  
Guillaume Vares ◽  
Gersende Alphonse ◽  
Alexandra Lauret ◽  
Caterina Monini ◽  
...  
Keyword(s):  
Epithelial To Mesenchymal Transition ◽  
Ion Irradiation ◽  
Migration And Invasion ◽  
X Rays ◽  
New Paradigm ◽  
Mesenchymal Transition ◽  
Carbon Ion ◽  
Stem Cell Migration ◽  
Hypoxic Conditions ◽  
Production And Distribution

Although conventional radiotherapy promotes the migration/invasion of cancer stem cells (CSCs) under normoxia, carbon ion (C-ion) irradiation actually decreases these processes. Unraveling the mechanisms of this discrepancy, particularly under the hypoxic conditions that pertain in niches where CSCs are preferentially localized, would provide a better understanding of the origins of metastases. Invasion/migration, proteins involved in epithelial-to-mesenchymal transition (EMT), and expression of MMP-2 and HIF-1α were quantified in the CSC subpopulations of two head-and-neck squamous cell carcinoma (HNSCC) cell lines irradiated with X-rays or C-ions. X-rays triggered HNSCC-CSC migration/invasion under normoxia, however this effect was significantly attenuated under hypoxia. C-ions induced fewer of these processes in both oxygenation conditions. The differential response to C-ions was associated with a lack of HIF-1α stabilization, MMP-2 expression, or activation of kinases of the main EMT signaling pathways. Furthermore,we demonstrated a major role of reactive oxygen species (ROS) in the triggering of invasion/migration in response to X-rays. Monte-Carlo simulations demonstrated that HO● radicals are quantitatively higher after C-ions than after X-rays, however they are very differently distributed within cells. We postulate that the uniform distribution of ROS after X-rays induces the mechanisms leading to invasion/migration, which ROS concentrated in C-ion tracks are unable to trigger.

scholarly journals Laboratory Simulations of Physico-chemical Processes under Interstellar Conditions

2012 ◽  
Vol 10 (H16) ◽  
pp. 713-714
Author(s):  
Guillermo M. Muñoz Caro
Keyword(s):  
Ion Irradiation ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Photon Flux ◽  
X Rays ◽  
Dust Grains ◽  
Dark Cloud ◽  
Interstellar Clouds ◽  
Laboratory Simulations ◽  
Gas Molecules

AbstractThe accretion and desorption of gas molecules on cold dust grains play an important role in the evolution of dense clouds and circumstellar regions around YSOs. Some of the gas molecules detected in interstellar clouds were likely synthesized in icy dust grains and ejected to the gas. But in dark cloud interiors, with temperatures as low as 10–20 K, thermal desorption is negligible and a non-thermal mechanism like ice photodesorption is required. Reactions in the ice matrix are driven by energetic processing such as photon and ion irradiation. In circumstellar regions the photon flux (UV and X-rays) is expected to be significantly higher than in dense cloud interiors, icy grain mantles present in the outer parts will experience significant irradiation. The produced radicals lead to the formation of new species in the ice, some of them of prebiotic interest. Laboratory simulations of these processes are required for their understanding. The new ultra-high vacuum set-ups introduce some important improvements.

scholarly journals Production of early and late nuclear DNA damage and extracellular 8-oxodG in normal human skin fibroblasts after carbon ion irradiation compared to X-rays

2018 ◽  
Vol 52 ◽  
pp. 116-121 ◽  
Author(s):  
Virginie Prevost ◽  
François Sichel ◽  
Ivannah Pottier ◽  
Alexandre Leduc ◽  
Stéphanie Lagadu ◽  
...  
Keyword(s):  
Dna Damage ◽  
Human Skin ◽  
Nuclear Dna ◽  
Ion Irradiation ◽  
Skin Fibroblasts ◽  
X Rays ◽  
Human Skin Fibroblasts ◽  
Normal Human Skin ◽  
Carbon Ion ◽  
Normal Human

scholarly journals Silencing of lncRNA H19 Enhances the Sensitivity to X-rays and Carbon-Ions Through the miR-130a-3p /WNK3 Signal Axis in Non-Small-Cell Lung Cancer Cells

2021 ◽  
Author(s):  
Xueshan Zhao ◽  
Xiaodong Jin ◽  
Qiuning Zhang ◽  
Ruifeng Liu ◽  
Hongtao Luo ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Small Cell Lung Cancer ◽  
Cell Lung Cancer ◽  
Therapeutic Target ◽  
Ion Irradiation ◽  
Expression Profiles ◽  
Small Cell ◽  
X Rays ◽  
Small Cell Lung ◽  
Carbon Ion

Abstract Background: LncRNA H19 was believed to act as an oncogene in various types of tumors and was considered to be a therapeutic target and diagnosis marker. However, the role of lncRNA H19 in regulating the radiosensitivity of non-small cell lung cancer (NSCLC) cells was unknown. However, the effects of lncRNA H19 on radiosensitivity of NSCLC were not clear. Methods: The expression profiles of lncRNAs were explored via transcriptome sequencing in NSCLC. The CCK-8, EDU, and clonogenicity survival assay were conducted to explore the proliferation and radiosensitivity in NSCLC cells. Results: Expression patterns of lncRNAs revealed that compared with A549 cells, lncRNA H19 was upregulated in radioresistant NSCLC(A549-R11) cells. Knockdown experiments revealed that lncRNA H19 enhanced the radiation sensitivity of both A549 and H460 cancer cell lines to X-rays and carbon ion irradiation. Mechanistically, lncRNA H19 upregulated With-No-Lysine Kinase 3 (WNK3) expression via serving as a sponge of miR-130a-3p and promoted the resistance of NSCLC cells to both X-rays and carbon ion irradiation. Conclusion: Knockdown of lncRNA H19 promoted the radiation sensitivity of NSCLC cells to X-rays and carbon ion irradiation. Hence, lncRNA H19 might function as a potential therapeutic target which enhance the anti-tumor effects of radiotherapy in NSCLC.

scholarly journals Mitochondrial DNA Mutations Induced by Carbon Ions Radiation: A Preliminary Study

Dose-Response ◽  
2018 ◽  
Vol 16 (3) ◽  
pp. 155932581878984
Author(s):  
Yong Chen ◽  
Haining Gao ◽  
Wenling Ye
Keyword(s):  
Mitochondrial Dna ◽  
Nuclear Dna ◽  
Ion Irradiation ◽  
Direct Sequencing ◽  
Point Mutations ◽  
Heavy Ion ◽  
X Rays ◽  
Carbon Ions ◽  
Mtdna Mutations ◽  
Heavy Ion Irradiation

Heavy-ion irradiation-induced nuclear DNA damage and mutations have been studied comprehensively. However, there is no information about the deleterious effect of heavy-ion irradiation on mitochondrial DNA (mtDNA). In this study, 2 typical mtDNA mutations were examined, including 4977 deletions and D310 point mutations. The 4977 deletions were quantified by real-time polymerase chain reaction, and D310 point mutations were analyzed by direct sequencing and a specific enzyme digestion genotyping method. Results showed that carbon ions radiation can induce temporal fluctuation of mtDNA 4977 deletions in 72 hours after irradiation, while survived clones were free from this deletion. Carbon ions induced more D310 mutations than X-rays, and the single-cell heteroplasmy was eliminated. This is the first study investigating mtDNA mutations induced by carbon ions irradiation in vitro. These findings would provide fundamental information for further investigation of radiation-induced mitochondrial biogenesis.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

Emergence of Twisted Magnetic Flux Related Sigmoidal Brightening

2000 ◽  
Vol 179 ◽  
pp. 263-264
Author(s):  
K. Sundara Raman ◽  
K. B. Ramesh ◽  
R. Selvendran ◽  
P. S. M. Aleem ◽  
K. M. Hiremath
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Ultra Violet ◽  
Active Regions ◽  
Morphological Properties ◽  
Energy Storage And Conversion ◽  
The Sun ◽  
X Rays ◽  
The Magnetic Field

Extended AbstractWe have examined the morphological properties of a sigmoid associated with an SXR (soft X-ray) flare. The sigmoid is cospatial with the EUV (extreme ultra violet) images and in the optical part lies along an S-shaped Hαfilament. The photoheliogram shows flux emergence within an existingδtype sunspot which has caused the rotation of the umbrae giving rise to the sigmoidal brightening.It is now widely accepted that flares derive their energy from the magnetic fields of the active regions and coronal levels are considered to be the flare sites. But still a satisfactory understanding of the flare processes has not been achieved because of the difficulties encountered to predict and estimate the probability of flare eruptions. The convection flows and vortices below the photosphere transport and concentrate magnetic field, which subsequently appear as active regions in the photosphere (Rust & Kumar 1994 and the references therein). Successive emergence of magnetic flux, twist the field, creating flare productive magnetic shear and has been studied by many authors (Sundara Ramanet al.1998 and the references therein). Hence, it is considered that the flare is powered by the energy stored in the twisted magnetic flux tubes (Kurokawa 1996 and the references therein). Rust & Kumar (1996) named the S-shaped bright coronal loops that appear in soft X-rays as ‘Sigmoids’ and concluded that this S-shaped distortion is due to the twist developed in the magnetic field lines. These transient sigmoidal features tell a great deal about unstable coronal magnetic fields, as these regions are more likely to be eruptive (Canfieldet al.1999). As the magnetic fields of the active regions are deep rooted in the Sun, the twist developed in the subphotospheric flux tube penetrates the photosphere and extends in to the corona. Thus, it is essentially favourable for the subphotospheric twist to unwind the twist and transmit it through the photosphere to the corona. Therefore, it becomes essential to make complete observational descriptions of a flare from the magnetic field changes that are taking place in different atmospheric levels of the Sun, to pin down the energy storage and conversion process that trigger the flare phenomena.

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