• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1671-1676
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• 2023

The influence of adding iodine as a contrast substance to elevate radiation in a tumor is studied using simulation techniques of Monte-Carlo. The study is carried on a brain cancer by adopting an unsophisticated head phantom. The ionizing radiation source is an external beam of x-rays with energy range of a few tens of keV. The expected radiation dose increment due to adding the iodine is investigated by comparing the radiation in the tumor after and before adding the iodine and calculating the ratio between the two doses. Several concentrations of the contrast substance are used to quantify its impact. The change of the dose increment with the source energy is also examined. It is found that the radiation elevation in the tumor tends to saturate with increasing the iodine concentration, and for the studied domain of energies (30 keV-100 keV), the radiation dose enhancement factors (RDEF) for the different iodine concentrations (1%-9%) show peaked curves, with the peak occurring between 60 keV and 70 keV. For the highest concentration studied, 9%, the peak value is almost 7.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3572-3578
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• 2011

In Positron Emission Tomography Computed Tomography, Standardized Uptake Value(SUV)is most generally used to discern tumors. However, SUV may be influenced other factors. In this study, experiment was conducted distrotion in image and change in SUV according to substance with GEMINI TF PET/CT of Philips.. SUV for materials resulted in 1.8 for stainless, 1.4 for stent, 2.4 for iodine contrast medium, 2.6 for Barium Sulfate, 1.6 for Gypsum, and 1.4 for paraffin respectively. The distortion of image was remarkable for the iodine contrast medium and Barium Sulfate. For the barium sulfate, the higher the density, the larger the distrotion of the images. As a result of test, it appeared that the metallic substance whose atomic number is low and contrast medium whose concentration is low didn't affect the distortion in image and the change in SUV. However, it tis necessary to minimize distortion in image and change in SUV, by removing the metallic substance and checking if there are contrast mdeium or before examination.

• Journal of Magnetics
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• v.20 no.3
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• pp.302-307
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• 2015

The purpose of the study was to identify how isotope and magnetic resonance imaging (MRI) contrast media impact on noise to computed tomography (CT) examination. For the study, divide the phantoms to two groups: 1) saline, saline + different kinds of contrast agent without $^{99m}Tc$ administration; 2) $^{99m}Tc$ administration: saline, saline + different kinds of contrast agent with $^{99m}Tc$ administration. CT contrast agent was used for Iopamidol$^{(R)}$ and Dotarem. And MRI contrast agent was used for Primovist$^{(R)}$ and Gadovist$^{(R)}$. To obtain an image, we used CT scanner. With an obtained image, we set the $1cm^2$ region of interest in the middle of bottle to measure the noise and CT number. As a result, there was no difference in CT number before and after inserting $^{99m}Tc$ into all contrast media including Normal Saline. However, when it comes to Noise, there was a difference before and after inserting $^{99m}Tc$ into every contrast media except MRI contrast media such as Primovist$^{(R)}$ and Gadovist$^{(R)}$.

• Korean Journal of Pharmacognosy
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• v.7 no.4
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• pp.233-235
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• 1976

Substances $I{\sim}VII$ are isolated from the root of Glehnia littoralis which has been often used as a subsitute of Bang-Poong in Korea. White needle crystalline substance of $C_{29}H_{50}O$, m.p. $137{\sim}139^{\circ}C$ was confirmed as ${\beta}-sitosterol$ through elemental analysis, derivative synthesis, IR and physicochemical tests. Moreover, it was concluded that white needle crystal of $C_{12}H_{8}O_{4}$, m.p. $188{\sim}189^{\circ}$ was confirmed as bergapten, through a contrast test with standard substance and by UV and IR-spectra. It was found that substance III and VII coincided with the Rf values of imperatorin and umbelliferone and to its colors under the UV-ray, and its similarity to UV-spectrum can be recognized, but their melting points are remarkedly different respectively.

• Journal of radiological science and technology
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• v.41 no.2
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• pp.103-107
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• 2018

In MR, the iodine CT contrast medium reduces the T1 and T2 relaxation times of the substance, resulting in a change in signal intensity. This study aimed to measure the relaxation rate of MR contrast medium with or without diluting CT contrast medium and analyzed the effect of CT contrast medium. Undiluted Gadoteridol solution was diluted with saline to prepare MR contrast medium phantoms with various levels of Gadoteridol concentrations. Moreover, undiluted Iomeprol was mixed with the prepared MR contrast medium phantoms at 1:1 ratio to make MR contrast medium phantoms with containing CT contrast medium for the experiment. T1 and T2 mappings were conducted to quantitatively evaluate the relaxation time and relaxation rate of these phantoms. The results showed that the T1 and T2 relaxation time and relaxation rate of MR contrast medium diluted with CT contrast medium were significantly (p<0.05) shorter than those of MR contrast medium not diluted with CT contrast medium. The results of this study imply that, when MR contrast medium shall be used after injecting CT contrast medium, CT contrast medium should be discharged enough. Moreover, it would be desirable to conduct CT test after taking MRI test in order to reduce the effects of CT contrast medium on MR contrast medium.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.183-189
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• 2014

Purpose : Intravenous contrast medium is a substance used to enhance the contrast of normal tissues or malignant tissues within the body. For this reason, intravenous contrast media have been extensively used form treatment-planning CT. However, when the patient is receiving proton therapy, there is no contrast medium in that moment. In this study, evaluate the influence of intravenous contrast medium on proton range and Spread-Out Bragg peak(SOBP) in Treatment Planning System(TPS). Materials and Methods : Hounsfield Unit(HU) value were measured by 20 liver cancer patients with phase change. and evaluate the proton range and SOBP on 5 liver proton treatment plan. By using the hand made water phantom measure the proton range and SOBP on proton treatment plan with changing HU and Depth. Results : Changing value(Pre contrast, Arterial phase, Portal phase) in liver cancer patient were ($58{\pm}5.7$, $75{\pm}9.5$, $117{\pm}14.6$ for liver tissue) and ($40{\pm}6.1$, $279{\pm}49.0$, $154{\pm}22.8$ for aorta), respectively. The mean difference of range was 2.5mm and SOBP was 1.4mm according to HU change. In phantom study, proton range was shorter and SOBP was narrowed with increasing HU. Conclusion : We verify that HU change lead to range and SOBP change in TPS. Additional study is required to verify that change of HU make range and SOBP be changed in actual substance.

• Acta Via Serica
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• v.3 no.1
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• pp.85-102
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• 2018

This study aims to contrast phonological characteristics of Korean and Turkish in terms of language universality. Considering consonants, both languages have the same number of consonants (21), which is the most typologically plausible structure of consonants. Thus, it can be said that they display high universality in the number of consonants. However, Turkish shows higher universality in regards to their substance, i.e., it differs from Korean when it comes to the structure of plosives and affricates. Turkish has two contrastive consonants, i.e., voiced and voiceless. However, the Korean plosives and affricates consist of neutral, tense and aspirate voiceless. In the case of vowels, both Korean with 10 vowels and Turkish with 8 vowels show lower universality. Yet, all of those vowels belong to the list of the most plausible vowels which makes their universality higher in substance. In respect of the syllable structure, Korean with its (C)V(C) type shows a moderately complex structure while Turkish with its (C)V(C)(C) type has a complex structure. The coda may consist of two consonants in Turkish while only one consonant is possible in Korean. However, onset is composed of one consonant in both languages. The contrastive study of similarities and differences between Korean and Turkish in terms of phonological characteristics will help not only understand the two languages but also provide useful information to increase the efficacy of Korean language education for Turkish learners of Korean, whose number is rapidly increasing.

• Cross-Cultural Studies
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• v.35
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• pp.293-314
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• 2014

This paper aims to contrast phonology of Korean and Thai in terms of language universality. Considering consonants, both languages having 21 typologically most plausible consonants display high universality in the number of consonants. However, Thai shows higher universality in regards to their substance, i.e. it differs from Korean when it comes to the structure of plosives and fricatives. Both Korean and Thai show similarities regarding the plosives due to the fact that both languages possess three contrastive consonants. However, the Thai plosives consist of plain voiced, plain voiceless and aspirated voiceless sounds that have higher universality than the Korean plosives which are plain voiced, plain voiceless and aspirated voiceless. In case of vowels, both Korean with its 10 vowels and Thai with its 9 vowels show lower universality when it comes to the total number of vowels. However, all of those vowels belong to the list of most plausible vowels which makes their universality higher in substance. In respect of syllable structure, Korean with its CVC type shows a moderately complex structure while Thai with its CCVC type has a complex structure. The coda may consist of only one consonant in each language but onset is composed of one consonant in Korean, and two consonants in Thai. The contrastive study of similarities and differences between Korean and Thai in terms of phonology will help not only understand the two languages but also provide useful information for increasing the efficacy of Korean language education for Thai learners of Korean whose number is rapidly increasing.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.695-701
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• 1995

The ethanol extract of leaf mustard(Brassica juncea) exhibiting high antimicrobial activities was fractionated in the order of hexane, chloroform, ethylacetate and butanol fractions to test antimicrobial activity. The highest antimicrobial activity for the bacteria tested was found in the ethylacetate fraction, but a lesser extent in the butanol fraction. In contrast to antimicrobial activity for the bacteria, both ethylacetate and butanol fractions showed weak antimicrobial activity for yeasts. Unknown compound A in the ethylacetate fraction which exhibited a strong antimicrobial activity was isolated by silica gel column chromatography and HPLC, and exhibited 9 times more antimicrobial activity than the ethylacetate fraction.

• Journal of Microbiology
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• v.40 no.2
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• pp.178-181
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• 2002

Streptomycete isolator strain M0137 showed cytotoxic effect on THP-1 cells. One of the purified substances produced from the strain was identified as nonadecanoic acid. Morphological and physiological properties, phylogenetic analysis, and genomic fingerprinting of strain M0137 were determined. Strain M0137 showed a high similarity with Streptomyces scabiei, phenotypically and phylogenetically. In contrast, genomic fingerprinting and G+C content analysis revealed that strain M0137 could be distinguished from S. scabiei ATCC49173$\^$T/. We propose to name strain M0137 as Streptomyces scabiei Subsp.