• The Korean Journal of Nuclear Medicine
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• v.31 no.4
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• pp.433-439
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• 1997

$^{166}Ho$-chitosan complex, or $^{166}Ho$-CHICO, is a candidate pharmaceutical for intracavitary radiation therapy of cystic brain tumors because of the desirable nuclear characteristics of $^{166}Ho$ for therapeutic use and the suitable biological and chemical characteristics of chitosan, not to mention its ready producibility The amount of $^{166}Ho$-CHICO to be administered to obtain the goal therapeutic effect can be suggested by predicting the dose to the cyst wall for a varying pharmaceutical dose. When $^{166}Ho$-CHICO is infused into the cyst, the major part of the energy delivery by beta particles emitted from $^{166}Ho$ occurs in the cyst wall within 4mm in depth from the cyst wall surface. Also, realizing the attachment of $^{166}Ho$-CHICO to the cyst wall surface would change the predictions of dose to the cyst wall.

• Food Science and Preservation
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• v.14 no.5
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• pp.451-456
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• 2007

The vitamin C content in extruded comstarch matrix was shown to depend on extrusion process variables (barrel temperature and water content), the packaging method, and the storage period. In addition, loss rates of vitamin C under different processing conditions were calculated. Extrusion process variable were barrel temperature ($80^{\circ}C,\;90^{\circ}C,\;100^{\circ}C$ and $110^{\circ}C$), and water content (25% 30% both w/w). The vitamin C content decreased as barrel temperature increased from $80^{\circ}C$ to $110^{\circ}C$ and water content increased from 25% to 30% when either LDPE plastic film packaging or ON film vacuum packaging were employed. As barrel temperature and water content increased, vitamin C decreased in comstarch packed in either LDPE film or ON film. As temperature increased, vitamin C loss rate increased under both packaging conditions, but the loss tate was only 50% of the LDPE film packaging rate when ON film vacuum packaging was used. In conclusion, the higher the temperature, and the greater the water content, the less vitamin C was inactivated during extrusion cooking, although the loss rah of vitamin C became faster as temperature and water content rose. In conclusion, extrusion process could be applied for making vitamin C matrix to extend vitamin C preservation.

• The Korean Journal of Nuclear Medicine
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• v.34 no.1
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• pp.62-73
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• 2000

Purpose: Esophageal cancer patients have a difficulty in the intake of meals through the blocked esophageal lumen, which is caused by an ingrowth of cancer cells and largely influences on the prognosis. It is reported that esophageal cancer has a very low survival rate due to the lack of nourishment and immunity as the result of this. In this study a new radioactive stent, which prevents tumor ingrowth and restenosis by additional radiation treatment, has been developed. Materials and Methods: Using ${\ulcorner}HANARO{\lrcorner}$ research reactor, the radioactive stent assembly ($^{166}Ho$-SA) was prepared by covering the metallic stent with a radioactive sleeve by means of a post-irradiation and pre-irradiation methods. Results: Scanning electron microscopy and autoradiography exhibited that the distribution of $^{165/166}Ho\;(NO_3)$ compounds in polyurethane matrix was homogeneous. A geometrical model of the esophagus considering its structural properties, was developed for the computer simulation of energy deposition to the esophageal wall. The dose distributions of $^{166}Ho$-stent were calculated by means of the EGS4 code system. The sources are considered to be distributed uniformly on the surface in the form of a cylinder with a diameter of 20 mm and length of 40 mm. As an animal experiment, when radioactive stent developed in this study was inserted into the esophagus of a Mongrel dog, tissue destruction and widening of the esophageal lumen were observed. Conclusion: We have developed a new radioactive stent comprising of a radioactive tubular sleeve covering the metallic stent, which emits homogeneous radiation. If it is inserted into the blocked or narrowed lumen, it can lead to local destruction of the tumor due to irradiation effect with dilatation resulting from self-expansion of the metallic property. Accordingly, it is expected that restenosis esophageal lumen by the continuous ingrowth and infiltration of cancer after insertion of our radioactive stent will be decreased remarkably.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.70-75
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• 2012

Purpose: It is important to acquire accurate data because the SPECT scan affected by various physical factors. The aim of this study was to compare the uniformity when both centers were matched or mismatched differed from position of heart in COR. Materials and methods: The images were acquired with cylindrical uniform phantom (6.7 cm diameter, 9 cm length) and heart insert phantom using Cardio MD SPECT system (Philips, USA). The phantoms were positioned on COR as well as four different points which were 10 cm above, below, left and right side from the COR. The counts from the both edge of cylindrical uniform phantom and those from the both wall of heart insert phantom were compared by using vertical and horizontal line profile. In addition, the qualitative evaluation was performed with heart insert phantom images and volunteer test. Results: In heart insert phantom study, the differences of counts between COR and 10 cm above, below, left and right point of COR were 1.1, 4.1, 4.9, 2.2 and 0.9% using T-A curve for horizontal view. In case of vertical view of COR 3.9, 21.9, 3.5, 23.9, 14.0% were shown. In cylindrical phantom study, the differences of counts between COR and 10 cm above, below, left and right point of COR were 4.3, 0.3, 3.3, 2.6 and 0.7% using T-A curve for horizontal view. In case of vertical view of COR 2.7, 3.0, 1.0, 0.3, 3.4% were shown. For qualitative evaluation, the images at COR were the most uniform for both of heart insert phantom and volunteer test, whereas other four positions showed somewhat distorted images. Conclusion: It showed the most uniform images when COR is matched with the heart. Therefore, we can expect that distortion which increased or decreased of myocardial perfusion will be prevented by matching the heart and COR when positioning. Furthermore, the accuracy of diagnosis will be improved as well.

• Applied Biological Chemistry
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• v.29 no.4
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• pp.359-365
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• 1986

Exponentially growing cells of S. cerevisiae were cultivated in the concomitant presence of $2{\times}10^{-3}\;M$ paraquat for 12 hours. Cellular growth became slower as the time passed and then, it was completely inhibited after 6 hours of cultivation. More than 70 percent of the yeast cells were killed with in 12 hours of paraquat treatment. It was observed that size of the yeast cell varied from $4.5{\times}5.5{\um}m$ to $2.5{\times}3.5{\um}m$ in diameter, while that of control was uniform. The number of budding cells became rare, Cell wall of the paraquat treated cell was thinner$(0.15{\mu}m)$ than that of control cell$(0.20{\mu}m)$. Outer part of the cell wall had higher density than inner part. Membrane structures such as plasma membrane and mitochondria was decomposed during the paraquat treatment for 12 hours.

• Journal of the Korean Society of Radiology
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• v.85 no.1
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• pp.147-160
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• 2024

Purpose To define an MRI scoring system for differentiating xanthogranulomatous cholecystitis (XGC) from wall-thickening type gallbladder cancer (GBC) and compare the diagnostic performance of the scoring system with the visual assessment of radiologists. Materials and Methods We retrospectively analyzed 23 and 35 patients who underwent abdominal MRI and were pathologically diagnosed with XGC and wall-thickening-type GBC after surgery, respectively. Three radiologists reviewed all MRI findings. We defined a scoring system using these MRI findings for differentiating XGC from wall-thickening type GBC and compared the area under the curve (AUC) of the scoring system with the visual assessment of radiologists. Results Nine MRI findings showed significant differences in differentiating the two diseases: diffuse gallbladder wall thickening (p < 0.001), mucosal uniformity (p = 0.002), intramural T2-high signal intensity (p < 0.001), mucosal retraction (p = 0.016), gallbladder stones (p < 0.001), T1-intermediate to high-signal intensity (p = 0.033), diffusion restriction (p = 0.005), enhancement pattern (p < 0.001), and phase of peak enhancement (p = 0.008). The MRI scoring system showed excellent diagnostic performance with an AUC of 0.972, which was significantly higher than the visual assessment of the reviewers. Conclusion The MRI scoring system showed better diagnostic performance than the visual assessment of radiologists to differentiate XGC from wall-thickening-type GBC.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.3
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• pp.236-244
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• 2011

Purpose: This study was aimed to compare the margin and internal fitness of 3-unit zirconia bridge cores fabricated by several CAD/CAM systems using replica technique. Materials and methods: Three unit-bridge models in which upper canine and upper second premolar were used as abutments and upper first premolar was missed, were fabricated. Fourty models were classified into 4 groups (Cerasys$^{(R)}$ (Group C), Dentaim$^{(R)}$ (Group D), KaVo Everest$^{(R)}$ (Group K), $Lava^{TM}$ (Group L)), and zirconia cores were fabricated by each company. Sixteen points were measured on each abutment by replica technique. Statistical analysis was accomplished with two way ANOVA and Dunnett T3 (${\alpha}$=.05). Results: In most systems, there was a larger gap on inter margin than outer margin. In the Group K, overall fitness was excellent, but the incisal gap was very large. In the Group C, marginal gap was significantly larger than Group K, but overall internal gap was uniform (P<.05). The axial gap was under $100\;{\mu}m$ in all system. The difference between internal and external gap was small on Group L and C. However, internal gap was significantly larger than external gap in Group D (P<.05). The fitness of canine was better than second premolar among abutments (P<.05). Conclusion: The marginal and internal gap was within the clinically allowed range in all of the three systems. There was a larger gap on second premolar than canine on internal and marginal surface. In most systems, there was a larger gap on occlusal surface than axial surface.