• Macromolecular Research
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• v.10 no.6
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• pp.332-338
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• 2002

The effect of an electron beam and ${\gamma}$-ray irradiation on the curing of epoxy resins was investigated. Diglycidyl ether of bisphenol A (DGEBA) and diglycidyl ether of bisphenol F (DGEBF) as epoxy resin were used. The epoxy resins containing 1.0-3.() wt% of triarylsulphonium hexafluoroantimonate(TASHFA) and triarylsulphonium hexafluorophosphate(TASHFP) as initiator were irradiated under nitrogen at room temperature with different dosage of EB and ${\gamma}$-rays from a Co$^{60}$ u source. The chemical and mechanical characteristics of irradiated epoxy resins were compared after curing of EB and ${\gamma}$-ray irradiation. The thermal properties of cured epoxy were investigated using dynamic mechanical thermal analysis. The chemical structures of cured epoxy were characterized using near infrared spectroscopy. Mechanical properties such as flexural strength, modulus were measured. The gel fraction of DGEBA with ${\gamma}$-ray was higher than that of the epoxy with EB at the same dose. Young's modulus of the sample irradiated by ${\gamma}$-ray is higher than that of sample cured by EB. From the result of strain at yield, it was found that the epoxy cured by ${\gamma}$-ray had a higher stiff property compared with the irradiated by EB.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.9 no.1
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• pp.35-41
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• 2023

Photodynamic therapy (PDT), in which a photosensitizer (PS), light, and molecular oxygen are essential components, is a non-invasive and highly effective cancer therapeutic method. However, PDT suffers from the penetration limit of light caused by attenuation and scattering of light through tissues constraining its use to skin and endoscopically accessible cancers. Cerenkov luminescence (CL) is defined as the light illuminated when charged particles move in a dielectric medium at a velocity greater than the phase velocity of light. It is known that medical radioisotopes in preclinical and clinical settings have enough energy to generate CL, and lately, CL has been exploited as an excitation source for PDT without external light illumination. This review introduces state of the art studies of radioisotope-based PDT for cancer, in which radioisotopes are utilized as a light source.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.53-58
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• 2013

Purpose: To optimize correction method for SPECT/CT, image quality consisting of resolution and contrast was evaluated using three radioisotopes ($^{99m}Tc$, $^{201}Tl$ and $^{131}I$) and three different correction methods; attenuation correction (AC), scatter correction (SC) and both attenuation and scatter correction (ACSC). Materials and Methods: Images were acquired with a SPECT/CT scanner and a conventional CT protocol with an OESM reconstruction algorithm (2 iterations and 10 subsets). For resolution measurement, fixed radioactivity (2.22 kBq) was infused into a spatial resolution phantom and full width at half maximum (FWHM) was measured using a vendor-provided software. For contrast evaluation, radioactive source with a ratio of 1:8 to background was filled in a Flanged Jaszczak phantom and percent contrast (%) were calculated. All the parameters for image quality were compared with non-correction (NC) method. Results: As compared with NC, image resolution of all three isotopes were significantly improved by AC and ACSC, not by SC. In particular, ACSC showed better resolution than AC alone for $^{99m}Tc$ and $^{201}Tl$. Image contrast of all three radioisotopes in a sphere with the largest diameter were enhanced by all correction methods. ACSC showed the highest contrast in all three radioisotopes, which was the most accurate in $^{99m}Tc$ (85.9%). Conclusion: Image quality of SPECT/CT was improved in all the radioisotopes by CT-based attenuation correction methods, except SC alone. SC failed to improve resolution in any radioisotopes, but it was effective in contrast enhancement. ACSC would be the best correction method as it improved resolution in radioisotopes with low energy levels and contrast in radioisotope with low energy levels. However, in radioisotope with high energy level, AC would be better than ACSC for resolution improvement.

• Proceedings of the Korean Vacuum Society Conference
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• 2007.02a
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• pp.62-62
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• 2007

• The Korean Journal of Nuclear Medicine
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• v.7 no.1
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• pp.1-13
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• 1973

• Proceedings of the Korean Nuclear Society Conference
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• 2004.05a
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• pp.496.2-496.2
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• 2004

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.2
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• pp.135-144
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• 2019

Targeted alpha therapy (TAT) based on metallic radionuclides has attracted a lot of attention lately due to its impressive therapeutic efficacy displayed in couple of clinical studies for cancer. Representative metallic radionuclides emitting alpha-particle include 225Ac, 213Bi, and 227Th, and there have been variety of TAT formulations based on different targeting moiety and chelating agents. In this review, we introduce strategies to label metallic radioisotopes with biomolecules and look at some of recent preclinical and clinical results of TAT for cancer.

• Journal of the Korea Computer Industry Society
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• v.7 no.1
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• pp.7-14
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• 2006

In Korea, under the influence of the jurisdiction, usage of radioisotopes are limited. The limitation is $100[{\mu}Ci]$ or less. Therefore, in this study, basic data were designed, and the following data are needed in order to improve content measuring instrument which is suitable for radioisotopes limitation. Owing to the source and detector's properties, measuring instrument was designed geometrically, neutron and photon's particle transportation was analysed by using the MCNP code which is in Monte Carlo Method, also the location of source and detectors, geometrical structure of neutron absorber and moderator was designed.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.1091-1092
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• 2004

• Proceedings of the Korean Nuclear Society Conference
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• 2004.05a
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• pp.378-378
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• 2004