scholarly journals Chorioretinal Side Effects of Therapeutic Ocular Irradiation: A Multimodal Imaging Approach

2020 ◽  
Vol 9 (11) ◽  
pp. 3496
Author(s):  
Giulia Midena ◽  
Raffaele Parrozzani ◽  
Luisa Frizziero ◽  
Edoardo Midena
Keyword(s):  
Optic Neuropathy ◽  
Multimodal Imaging ◽  
Vascular System ◽  
Retinal Disease ◽  
Cellular Architecture ◽  
Imaging Approach ◽  
Radiation Induced ◽  
Retinal Complications

Radiation chorioretinopathy, radiation maculopathy, and radiation optic neuropathy are the major complications of ophthalmic radiotherapy. Optical coherence tomography (OCT) and OCT angiography (OCTA) are revolutionary imaging methods, allowing the visualization of the retinal cellular architecture and the retinal vascular system, respectively. In recent years this multimodal imaging approach has been applied to several retinal disease, but its role in the clinical characterization of retinal complications secondary to ophthalmic radiotherapy has not yet been defined. The purpose of this review is to critically evaluate the role of OCT and OCTA in the clinical assessment of radiation-induced chorioretinopathy, maculopathy, and optic neuropathy.

Dosimetric characterization of novel polycarbonate/porphyrin film dosimeters for high dose dosimetry: study on complexation effect

2018 ◽  
Vol 106 (8) ◽  
pp. 695-702 ◽  
Author(s):  
Eftekhar Sadat Noorin ◽  
Shahzad Feizi ◽  
Shahram Moradi Dehaghi
Keyword(s):  
Dose Range ◽  
Soret Band ◽  
Radiation Response ◽  
High Dose ◽  
Radiochromic Films ◽  
Experimental Parameters ◽  
Radiation Induced ◽  
Γ Rays

Abstract Two novel radiochromic films with 20 μm thickness were made from casting of solutions of polycarbonate (PC) containing 0.5 wt.% tetra phenyl porphyrin (TPPH2) and 5,10,15,20-tetraphenyl-21H,23H-porphine iron(III) chloride (Fe-TPP). Dosimetric characterization of the films as routine dosimeters were studied by spectrophotometric method. On subjecting TPPH2/PC and Fe-TPP/PC film dosimeters to gamma radiation, radiolytic bleaching of films was observed. The effects of metal-complexation on the radiation response of the film dosimeters were studied under 60Co γ-rays exposure in dose range of 0–100 kGy. The results were also compared with the PC/TPPF20 (PC/tetrakis (pentafluorophenyl) porphyrin) dosimeter to evaluate the substituent effect (role of fluorine groups). Experimental parameters including humidity, temperature and pre-irradiation (shelf-life) and post-irradiation storage in dark and in indirect sunlight were examined. The maximum absorbance of Soret band of dyes had meaningful shifts and reduction which arose from complexation and substituents. The dyed films characteristics were found to be stable enough in media with high degrees of temperature and humidity. The results indicate that the radiation-induced decoloration of TPPH2/PC and Fe-TPP/PC films can be reliably tuned and used in high dose dosimetry.

scholarly journals Role of total dose and hyperfractionation in reducing risk of radiation-induced optic neuropathy

2015 ◽  
Vol 8 (1) ◽  
pp. 75 ◽  
Author(s):  
NileshK Tumram ◽  
Dilip Kumre ◽  
Vijay Jeswani ◽  
Saket Benurwar
Keyword(s):  
Total Dose ◽  
Optic Neuropathy ◽  
Radiation Induced

CHARACTERIZATION OF THE OBESITY-HEART FAILURE WITH PRESERVED EJECTION FRACTION PHENOTYPE USING A MULTIMODAL IMAGING APPROACH

2018 ◽  
Vol 71 (11) ◽  
pp. A672
Author(s):  
Anupam Kumar ◽  
Bilal Ansari ◽  
Jessica Kim ◽  
Maheswara Reddy Koppula ◽  
Sowmya Gaddam ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ejection Fraction ◽  
Multimodal Imaging ◽  
Preserved Ejection Fraction ◽  
Imaging Approach

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

Applications of ultramicrotomy for materials characterization

1993 ◽  
Vol 51 ◽  
pp. 232-233
Author(s):  
R.T. Blackham ◽  
J.J. Haugh ◽  
C.W. Hughes ◽  
M.G. Burke
Keyword(s):  
Materials Science ◽  
Microstructural Analysis ◽  
Analytical Electron Microscopy ◽  
Austenitic Stainless Steels ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Thermally Induced ◽  
Radiation Induced ◽  
Characterization Of Materials

Essential to the characterization of materials using analytical electron microscopy (AEM) techniques is the specimen itself. Without suitable samples, detailed microstructural analysis is not possible. Ultramicrotomy, or diamond knife sectioning, is a well-known mechanical specimen preparation technique which has been gaining attention in the materials science area. Malis and co-workers and Glanvill have demonstrated the usefulness and applicability of this technique to the study of a wide variety of materials including Al alloys, composites, and semiconductors. Ultramicrotomed specimens have uniform thickness with relatively large electron-transparent areas which are suitable for AEM anaysis.Interface Analysis in Type 316 Austenitic Stainless Steel: STEM-EDS microanalysis of grain boundaries in austenitic stainless steels provides important information concerning the development of Cr-depleted zones which accompany M23C6 precipitation, and documentation of radiation induced segregation (RIS). Conventional methods of TEM sample preparation are suitable for the evaluation of thermally induced segregation, but neutron irradiated samples present a variety of problems in both the preparation and in the AEM analysis, in addition to the handling hazard.

Molecular Characterization of Radiation-induced Glioblastoma

2018 ◽  
Author(s):  
MY Deng ◽  
D Sturm ◽  
E Pfaff ◽  
GP Balasubrama ◽  
J Schittenhelm ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Radiation Induced
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