scholarly journals A radio-fluorogenic polymer-gel makes fixed fluorescent images of complex radiation fields

2018 ◽  
Author(s):  
John Warman ◽  
Matthijs deHaas ◽  
Leonard Luthjens ◽  
Antonia Denkova ◽  
Tiantian Yao
Keyword(s):  
Radioactive Isotope ◽  
Three Dimensional ◽  
Organic Polymer ◽  
X Rays ◽  
Polymer Gel ◽  
Tertiary Butyl ◽  
Pyrene Fluorescence ◽  
Radiation Fields ◽  
Radiation Induced ◽  
Γ Ray

Abstract: We review the development and application of an organic polymer-gel capable of producing fixed, three-dimensional fluorescent images of complex radiation fields. The gel consists for more than 99% of γ-ray-polymerized (~15% conversion) tertiary-butyl acrylate (TBA) containing ~100 ppm of a fluorogenic compound, e.g. maleimido-pyrene (MPy). The radio-fluorogenic effect depends on copolymerization of the MPy into growing chains of TBA on radiation-induced polymerization. This converts the maleimido residue, which quenches the pyrene fluorescence, into a succinimido moeity (SPy), which doesn't. The intensity of the fluorescence is proportional to the yield of free-radicals formed and hence to the local dose deposited. Because the SPy moieties are built into the cross-linked polymer matrix the image is fixed. The method of preparing the gel and imaging the radiation-induced fluorescence are presented and discussed. The effect is illustrated with fluorescent images of the energy deposited in the gel by beams of X-rays, electrons and protons as well as a radioactive isotope.

Principles of Trace Structure Analysis in Electron Microscopy

1975 ◽  
Vol 30 (9) ◽  
pp. 1188-1199
Author(s):  
W. Hoppe
Keyword(s):  
Structure Analysis ◽  
Three Dimensional ◽  
Main Idea ◽  
Chemical Processes ◽  
X Rays ◽  
Time Axis ◽  
Physico Chemical ◽  
Structural Work ◽  
Radiation Induced ◽  
Stable Molecule

Structure analysis done with X-rays or with electrons, corresponds to an averaging of the specimen configuration over the exposure time. Such an analysis leads to the structure of the specimen only if the configuration does not change during exposure or if the change is negligible (stable molecule, crystal). Some time ago for instable configurations the method of "trace structure analysis" was proposed. The present paper explains the general principles of this method in detail. The static image of the structure will be divided into a dynamic succession of images along the time axis ("three-dimensional film"). But this division is not really characteristic for the method (it is in fact trivial). The main idea is to work with non-significant three-dimensional elementary structures and to use redundancies of the radiation induced physico-chemical processes for the combination of these elementary structures. Obviously these "redundancy laws" can only be unravelled in detail by trace structural work. It will be shown further that for special classes of these laws correlation analysis and pattern recognition procedures can be applied

scholarly journals A Polymer-Gel Eye-Phantom for 3D Fluorescent Imaging of Millimetre Radiation Beams

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1195 ◽  
Author(s):  
Leonard Luthjens ◽  
Tiantian Yao ◽  
John Warman
Keyword(s):  
Uv Light ◽  
Thin Sheet ◽  
Three Dimensional ◽  
Vitreous Body ◽  
Fluorescent Imaging ◽  
Polymer Gel ◽  
Tertiary Butyl ◽  
Tomographic Images ◽  
Index Matching ◽  
Refractive Index Matching

We have filled a 24 mm diameter glass sphere with a transparent polymer-gel that is radio-fluorogenic, i.e., it becomes (permanently) fluorescent when irradiated, with an intensity proportional to the local dose deposited. The gel consists of >99.9% tertiary-butyl acrylate (TBA), pre-polymerized to ~15% conversion, and ~100 ppm maleimido-pyrene (MPy). Its dimensions and physical properties are close to those of the vitreous body of the human eye. We have irradiated the gel with a 3 mm diameter, 200 kVp X-ray beam with a dose rate of ~1 Gy/min. A three-dimensional (3D) (video) view of the beam within the gel has been constructed from tomographic images obtained by scanning the sample through a thin sheet of UV light. To minimize optical artefacts, the cell was immersed in a square tank containing a refractive-index-matching medium. The 20–80% penumbra of the beam was determined to be ~0.4 mm. This research was a preparatory investigation of the possibility of using this method to monitor the millimetre diameter proton pencil beams used in ocular radiotherapy.

Measurements in 3D images

1991 ◽  
Vol 49 ◽  
pp. 408-409
Author(s):  
John C. Russ
Keyword(s):  
Three Dimensional ◽  
Image Plane ◽  
X Rays ◽  
Traditional Use ◽  
3D Images ◽  
Confocal Scanning Laser Microscope ◽  
Hard Materials ◽  
Depth Direction ◽  
Confocal Scanning ◽  
Confocal Scanning Laser

Three-dimensional (3D) images consisting of arrays of voxels can now be routinely obtained from several different types of microscopes. These include both the transmission and emission modes of the confocal scanning laser microscope (but not its most common reflection mode), the secondary ion mass spectrometer, and computed tomography using electrons, X-rays or other signals. Compared to the traditional use of serial sectioning (which includes sequential polishing of hard materials), these newer techniques eliminate difficulties of alignment of slices, and maintain uniform resolution in the depth direction. However, the resolution in the z-direction may be different from that within each image plane, which makes the voxels non-cubic and creates some difficulties for subsequent analysis.

CONVENTIONAL VERSUS THREE-DIMENSIONAL CONFORMAL EXTERNAL RADIOTHERAPY IN CANCER CERVIX: A COMPARATIVE STUDY FOR COMPLIANCE, RESPONSE AND TOXICITY

2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Richa Gupta ◽  
Piyush Kumar ◽  
D. P. Singh ◽  
Arvind Kumar Chauhan ◽  
Kamal Sahni
Keyword(s):  
Clinical Response ◽  
Three Dimensional ◽  
Common Side Effect ◽  
P Value ◽  
High Dose ◽  
Cancer Cervix ◽  
Conventional Radiotherapy ◽  
Radiation Fields ◽  
Group A ◽  
Group B

INTRODUCTION: Cervical cancer is the second most frequent cancer among Indian women. Radiotherapy is the cornerstone of treatment in all its stages. Three-dimensional conformal radiotherapy (3DCRT) combines multiple radiation fields to deliver precise dose of radiation to the affected area. Tailoring each of the radiation fields to focus on the tumor delivers a high dose of radiation to the tumor and avoids nearby healthy tissue. The present study is done to compare conventional radiotherapy versus 3DCRT in cancer cervix for compliance, clinical response and toxicity. MATERIAL AND METHODS: Fifty patients were enrolled and randomised into two radiotherapy plans with radical intent - Group A treated by conventional radiotherapy and group B treated by 3DCRT. Concurrent cisplatin was delivered on weekly (35mg/m2) or tri-weekly (75mg/m2) basis during external beam Radiotherapy and was followed by High Dose Radiotherapy Brachytherapy. Clinical response and complication assessment were evaluated.Collected data was analyzed using standard statistical methods and softwares to calculate level of significance using “p” value by chi square test. RESULTS: In this study mean age of the patients was 48 years (26-67 years). The anemia was the most common side effect seen in both groups (96% vs 88%, p=0.29). Neutropenia was more in group B (36% vs 44%, p= 0.56). Lower GI toxicity was seen only in patients in group A (20% vs 0%, p=0.018). In follow up there were no significant early rectal and bladder reactions in both groups and 2 patients in each group had late rectal reactions of grade I and II (p= 0.312). No significant skin, bladder and small intestinal toxicity were seen in both groups. CONCLUSION: Conventional radiotherapy gives equally efficacious response though accompanied by toxicities which were acceptable.

scholarly journals Immunomodulatory Effects of Radiotherapy

2020 ◽  
Vol 21 (21) ◽  
pp. 8151
Author(s):  
Sharda Kumari ◽  
Shibani Mukherjee ◽  
Debapriya Sinha ◽  
Salim Abdisalaam ◽  
Sunil Krishnan ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Carbon Particle ◽  
Dna Lesions ◽  
X Rays ◽  
Adaptive Immune ◽  
High Let Radiation ◽  
Different Types ◽  
High Let ◽  
Radiation Induced ◽  
Tumor Death

Radiation therapy (RT), an integral component of curative treatment for many malignancies, can be administered via an increasing array of techniques. In this review, we summarize the properties and application of different types of RT, specifically, conventional therapy with x-rays, stereotactic body RT, and proton and carbon particle therapies. We highlight how low-linear energy transfer (LET) radiation induces simple DNA lesions that are efficiently repaired by cells, whereas high-LET radiation causes complex DNA lesions that are difficult to repair and that ultimately enhance cancer cell killing. Additionally, we discuss the immunogenicity of radiation-induced tumor death, elucidate the molecular mechanisms by which radiation mounts innate and adaptive immune responses and explore strategies by which we can increase the efficacy of these mechanisms. Understanding the mechanisms by which RT modulates immune signaling and the key players involved in modulating the RT-mediated immune response will help to improve therapeutic efficacy and to identify novel immunomodulatory drugs that will benefit cancer patients undergoing targeted RT.

scholarly journals Is Micro X-ray Computer Tomography a Suitable Non-Destructive Method for the Characterisation of Dental Materials?

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1271
Author(s):  
Andreas Koenig ◽  
Leonie Schmohl ◽  
Johannes Scheffler ◽  
Florian Fuchs ◽  
Michaela Schulz-Siegmund ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Computer Tomography ◽  
Mechanical Performance ◽  
Dental Materials ◽  
Three Dimensional ◽  
X Rays ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Multiple Measurements ◽  
High Doses

The aim of the study was to investigate the effect of X-rays used in micro X-ray computer tomography (µXCT) on the mechanical performance and microstructure of a variety of dental materials. Standardised bending beams (2 × 2 × 25 mm3) were forwarded to irradiation with an industrial tomograph. Using three-dimensional datasets, the porosity of the materials was quantified and flexural strength was investigated prior to and after irradiation. The thermal properties of irradiated and unirradiated materials were analysed and compared by means of differential scanning calorimetry (DSC). Single µXCT measurements led to a significant decrease in flexural strength of polycarbonate with acrylnitril-butadien-styrol (PC-ABS). No significant influence in flexural strength was identified for resin-based composites (RBCs), poly(methyl methacrylate) (PMMA), and zinc phosphate cement (HAR) after a single irradiation by measurement. However, DSC results suggest that changes in the microstructure of PMMA are possible with increasing radiation doses (multiple measurements, longer measurements, higher output power from the X-ray tube). In summary, it must be assumed that X-ray radiation during µXCT measurement at high doses can lead to changes in the structure and properties of certain polymers.

scholarly journals Differential Effects of Gold Nanoparticles and Ionizing Radiation on Cell Motility between Primary Human Colonic and Melanocytic Cells and Their Cancerous Counterparts

2021 ◽  
Vol 22 (3) ◽  
pp. 1418
Author(s):  
Elham Shahhoseini ◽  
Masao Nakayama ◽  
Terrence J. Piva ◽  
Moshi Geso
Keyword(s):  
Gold Nanoparticles ◽  
Ionizing Radiation ◽  
Cancer Cells ◽  
Cell Lines ◽  
Colorectal Adenocarcinoma ◽  
X Rays ◽  
Cell Adherence ◽  
Cancerous Cell ◽  
Primary Colon ◽  
Radiation Induced

This study examined the effects of gold nanoparticles (AuNPs) and/or ionizing radiation (IR) on the viability and motility of human primary colon epithelial (CCD841) and colorectal adenocarcinoma (SW48) cells as well as human primary epidermal melanocytes (HEM) and melanoma (MM418-C1) cells. AuNPs up to 4 mM had no effect on the viability of these cell lines. The viability of the cancer cells was ~60% following exposure to 5 Gy. Exposure to 5 Gy X-rays or 1 mM AuNPs showed the migration of the cancer cells ~85% that of untreated controls, while co-treatment with AuNPs and IR decreased migration to ~60%. In the non-cancerous cell lines gap closure was enhanced by ~15% following 1 mM AuNPs or 5 Gy treatment, while for co-treatment it was ~22% greater than that for the untreated controls. AuNPs had no effect on cell re-adhesion, while IR enhanced only the re-adhesion of the cancer cell lines but not their non-cancerous counterparts. The addition of AuNPs did not enhance cell adherence. This different reaction to AuNPs and IR in the cancer and normal cells can be attributed to radiation-induced adhesiveness and metabolic differences between tumour cells and their non-cancerous counterparts.

Visualizing Fluid Flows With X-Rays

2007 ◽  
Author(s):  
Theodore J. Heindel ◽  
Terrence C. Jensen ◽  
Joseph N. Gray
Keyword(s):  
Computed Tomography ◽  
Flow Visualization ◽  
Three Dimensional ◽  
Fluid Flows ◽  
X Rays ◽  
Radiographic Images ◽  
Optical Access ◽  
X Ray ◽  
X Ray Computed ◽  
Density Map

There are several methods available to visualize fluid flows when one has optical access. However, when optical access is limited to near the boundaries or not available at all, alternative visualization methods are required. This paper will describe flow visualization using an X-ray system that is capable of digital X-ray radiography, digital X-ray stereography, and digital X-ray computed tomography (CT). The unique X-ray flow visualization facility will be briefly described, and then flow visualization of various systems will be shown. Radiographs provide a two-dimensional density map of a three dimensional process or object. Radiographic images of various multiphase flows will be presented. When two X-ray sources and detectors simultaneously acquire images of the same process or object from different orientations, stereographic imaging can be completed; this type of imaging will be demonstrated by trickling water through packed columns and by absorbing water in a porous medium. Finally, local time-averaged phase distributions can be determined from X-ray computed tomography (CT) imaging, and this will be shown by comparing CT images from two different gas-liquid sparged columns.

scholarly journals Crocetin Mitigates Irradiation Injury in an In Vitro Model of the Pubertal Testis: Focus on Biological Effects and Molecular Mechanisms

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1676
Author(s):  
Giulia Rossi ◽  
Martina Placidi ◽  
Chiara Castellini ◽  
Francesco Rea ◽  
Settimio D'Andrea ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Molecular Mechanisms ◽  
Biological Effects ◽  
Cellular Damage ◽  
X Rays ◽  
Adolescent Cancer ◽  
Radiation Induced ◽  
Vitro Model ◽  
Underlying Mechanisms

Infertility is a potential side effect of radiotherapy and significantly affects the quality of life for adolescent cancer survivors. Very few studies have addressed in pubertal models the mechanistic events that could be targeted to provide protection from gonadotoxicity and data on potential radioprotective treatments in this peculiar period of life are elusive. In this study, we utilized an in vitro model of the mouse pubertal testis to investigate the efficacy of crocetin to counteract ionizing radiation (IR)-induced injury and potential underlying mechanisms. Present experiments provide evidence that exposure of testis fragments from pubertal mice to 2 Gy X-rays induced extensive structural and cellular damage associated with overexpression of PARP1, PCNA, SOD2 and HuR and decreased levels of SIRT1 and catalase. A twenty-four hr exposure to 50 μM crocetin pre- and post-IR significantly reduced testis injury and modulated the response to DNA damage and oxidative stress. Nevertheless, crocetin treatment did not counteract the radiation-induced changes in the expression of SIRT1, p62 and LC3II. These results increase the knowledge of mechanisms underlying radiation damage in pubertal testis and establish the use of crocetin as a fertoprotective agent against IR deleterious effects in pubertal period.

scholarly journals Dynamic three-dimensional observation of corner turning in LX-17 with flash x-rays

2020 ◽  
Author(s):  
Joseph W. Tringe ◽  
Michael B. Zellner ◽  
Clifton H. Mortensen ◽  
Franco J. Gagliardi ◽  
Jerel A. Smith ◽  
...  
Keyword(s):  
Three Dimensional ◽  
X Rays ◽  
Corner Turning
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