• The Korean Journal of Nuclear Medicine Technology
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• v.27 no.2
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• pp.111-127
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• 2023

Purpose: Gallium-68 (⁶⁸Ga) is increasingly used in nuclear medicine imaging for various conditions such as lymphoma and neuroendocrine tumors by labeling tracers like Prostate Specific Membrane Antigen (PSMA) and DOTA-TOC. However, compared to Fluorine-18 (¹⁸F) used in conventional nuclear medicine imaging, ⁶⁸Ga has lower spatial resolution and relatively higher Signal to Background Ratio (SBR). Therefore, this study aimed to investigate the optimized parameters and reconstruction methods for PET/CT imaging using the ⁶⁸Ga radiotracer through model-based image evaluation. Materials and Methods: Based on clinical images of ⁶⁸Ga-PSMA PET/CT, a NEMA/IEC 2008 PET phantom model was prepared with a Hot vs Background (H/B) ratio of 10:1. Images were acquired for 9 minutes in list mode using DMIDR (GE, Milwaukee WI, USA). Subsequently, reconstructions were performed for 1 to 8 minutes using OS-EM (Ordered Subset Expectation Maximization) + TOF (Time of Flight) + Sharp IR (VPFX-S), and BSREM (Block Sequential Regularized Expectation Maximization) + TOF + Sharp IR (QCFX-S-400), followed by comparative evaluation. Based on the previous experimental results, images were reconstructed for BSREM + TOF + Sharp IR / 2 minutes (QCFX-S-2min) with varying β-strength values from 100 to 700. The image quality was evaluated using AMIDE (freeware, Ver.1.0.1) and Advanced Workstation (GE, USA). Results: Images reconstructed with QCFX-S-400 showed relatively higher values for SNR (Signal to Noise Ratio), CNR (Contrast to Noise Ratio), count, RC (Recovery Coefficient), and SUV (Standardized Uptake Value) compared to VPFX-S. SNR, CNR, and SUV exhibited the highest values at 2 minutes/bed acquisition time. RC showed the highest values for a 10 mm sphere at 2 minutes/bed acquisition time. For small spheres of 10 mm and 13 mm, an inverse relationship between β-strength increase and count was observed. SNR and CNR peaked at β-strength 400 and then decreased, while SUV and RC exhibited a normal distribution based on sphere size for β-strength values of 400 and above. Conclusion: Based on the experiments, PET/CT imaging using the ⁶⁸Ga radiotracer yielded the most favorable quantitative and qualitative results with a 2 minutes/bed acquisition time and BSREM reconstruction, particularly when applying β-strength 400. The application of BSREM can enhance accurate quantification and image quality in ⁶⁸Ga PET/CT imaging, and an optimization process tailored to each institution's imaging objectives appears necessary.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.4
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• pp.259-267
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• 2001

This study was to investigate the effect of selenium on hepatic antioxidative defense system and oxidative damage in lead-administered rats. Male Sprague-Dawley rats weighing 140$\pm$5g were divided into one normal group(Se, 0 ppm) and three lead groups according to dietary levels of selenium supplementation: Pb0(Se, 0 ppm), PbS(Se, 0.5 ppm), and PbSS(Se, 1.0 ppm). All experimental groups were fed the experimental diet ad libitum for 4 weeks, and lead groups fed one containing 2,000 ppm lead acetate. Liver superoxide dismutase(SOD) activities in Pb0 group increased compared with other experimental groups. Liver gluthathione peroxidase(GSH-px) activities in Pb0 group decreased compared with normal group, but those of PbS and PbSS groups significantly increased compared with Pb0 group. Glutathione S-transferase(GST) activities decreased in Pb0 group and not significantly different from PbS and PbSS groups compared with normal group. Reduced glutathione(GSH) contents and GSH/GSSG of liver in Pb0 group were lower than those of other groups. Liver vitamin E contents in Pb0 group were about 50% of the normal group, but those of PbSS and PbS increased more than Pb0 group. Liver damage in electron microphotography process decreased in RER, showed an increase in Iysosome and also an increase in swelling of mitochondria. and ordered as follows : PbSS. PbS. and Pb0. It was concluded that high levels of dietary selenium had protective effects on peroxidative damage of hepatic cell accompanied with increased antioxidative defense system in lead-administered rats.

• Korean Journal of Community Nutrition
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• v.10 no.1
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• pp.3-11
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• 2005

The purpose of this study was to examine the long term effects of breast feeding on growth, bone development and nutrient intakes in preschool children. Subjects were 62 preschool children. Anthropometric characteristics and bone mineral density of carpus were measured using DEXA. The questionnaire was composed of health status, life style, dietary behaviors, and dietary intakes and was completed by the children's mothers. The average age of the boys was 62.4 months and that of the girls was 62.1 months. Average birth height and weight of the subjects was 50.9 cm and 3.4 kg for boys and 50.3 cm and 3.3 kg for girls, respectively. The average height, weight, $\%$ body fat, and obesity index were 111.7 cm, 19.6 kg, $15.0\%$, $-2.1\%$ in boys and 109.4 em, 18.7 kg, $17.5\%$, $0.2\%$ in girls, respectively. Forty children were fed colostrum, 21 were fed breast milk, 29 were fed formula, and 12 were fed mixed milk. There was no significant difference in growth status between children who were fed colostrum and those who were not. Children who had mixed feedings were significantly taller than those who did not (p <0.001), and children who had colostrum had significantly higher bone mineral density than those who did not ($0.25 \pm 0.04 g/ cm^2$ vs. $0.23 \pm 0.04 g/cm^2$, p < 0.05). However, the different feeding methods did not show any difference in bone mineral density. Except vitamin $B_6$, folic acid and vitamin E, vitamin, mineral and calorie intakes did not meet the Korean RDAs. Calcium intake was especially lower than recommendations by as much as $62\%$ and $70\%$ in boys and girls, respectively. There was no significant difference in nutrient intakes between children who had colostrum and those who did not. However, children who were formula consumed significantly more animal fat than those who did not (p < 0.05). Neonatal feeding and breast or formula feeding seems to associate with height, bone mineral density and animal fat intakes in preschool children, based on the results of this study. A longitudinal study is needed to clarify this relationship.

• Journal of Trauma and Injury
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• v.24 no.2
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• pp.143-150
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• 2011

Purpose: The object of this study is to compare the patient satisfaction in the view of scarring, cost, and hospital stay between the conventional suture method and a method using Histoacryl$^{(R)}$ (2-N-butylcyanoacrylate) adhesive for treating facial lacerations in the emergency department. Method: This study is a randomized prospective trial, which was conducted from December 2009 to January 2010. The participants include 109 patients who visited the emergency room in Deajon Eulji Medical Center. The ages ranged from 1 to 59 (mean age of 18.7), and all had facial lacerations of less than 3 cm. In order to treat the facial lacerations, an emergency medicine doctor used tissue adhesive (2-N-butylcyanoacrylate, Histoacryl$^{(R)}$) for 41 patients in the experimental group, and a plastic surgeon performed conventional suturing for 68 patients in the control group. The ER-stay and the primary treatment fee were compared in the two groups, and the scarring was evaluated 10 to 11 months from suturing by using the Modified Hollander Method and the 10-cm scaled VAS (visual analogue scale: score 0=no scar, score 10=very severe scar) Result: The ER stay was 76 minutes for the experimental group and 107 minutes for the control group, showing that statistically significantly less time of 31 minutes was taken in the experimental group. The cost of the experimental group was 40000 won (50.1%) more expensive than the control group, with an average cost of 121900 won for the experimental group and 81200 won for the control group. As for scar evaluation, 10.56 months after suturing, the experimental group showed a better result with a score of 2.6 compared to a score of 3.4 in the control group; however, this difference was not statistically significant ($p$ <0.05). As to a detailed evaluation of scar characteristics, the experimental group had a statistically significantly better result in scar elevation, with a score of 0.6 compared to a score of 1.65 for the control group. Conclusion: If appropriate patients are selected, the method using tissue adhesive directly applied by an EM doctor not only decreases ER stay but also creates similar patients satisfaction, with statistically better result in scar elevation, compared to the conventional suture method; thus, ultimately general patient satisfaction is increased.

• BMB Reports
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• v.39 no.2
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• pp.216-222
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• 2006

In the present study, we compared six different solubilization buffers and optimized two-dimensional electrophoresis (2-DE) conditions for human lymph node proteins. In addition, we developed a simple protocol for 2-D gel storage. Efficient solubilization was obtained with lysis buffers containing (a) 8M urea, 4% CHAPS (3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate), 40 mM Tris base, 65 mM DTT(dithiothreitol) and 0.2% carrier ampholytes; (b) 5M urea, 2M thiourea, 2% CHAPS, 2% SB 3-10 (N-decyl-N, N-dimethyl-3-ammonio-1-propanesulfonate), 40mM Tris base, 65 mM DTT and 0.2% carrier ampholytes or (c) 7M urea, 2M thiourea, 4% CHAPS, 65 mM DTT and 0.2% carrier ampholytes. The optimal protocol for isoelectric focusing (IEF) was accumulated voltage of 16,500 Vh and 0.6% DTT in the rehydration solution. In the experiments conducted for the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), best results were obtained with a doubled concentration (50 mM Tris, 384 mM glycine, 0.2% SDS) of the SDS electrophoresis buffer in the cathodic reservoir as compared to the concentration in the anodic reservoir (25 mM Tris, 192 mM glycine, 0.1% SDS). Among the five protocols tested for gel storing, success was attained when the gels were stored in plastic bags with 50% glycerol. This is the first report describing the successful solubilization and 2D-electrophoresis of proteins from human lymph node tissue and a 2-D gel storage protocol for easy gel handling before mass spectrometry (MS) analysis.

• Journal of the Korean Geophysical Society
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• v.6 no.3
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• pp.165-177
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• 2003

The purpose of this paper is to analyze the behavior and to study the safety evaluation of the Unmun Dam located in Cheongdo-Gun of GyeongBuk Province, Korea. For this purpose, soil analyses including boring data, geophysical surveys were conducted. In this paper, especially many geophysical methods were adopted to configure out the subsurface situation of dam. Applied geophysical methods were: 1) electric resistivity survey, 2) high frequency magnetotelluric (HFMT) survey, 3) ground penetrating radar (GPR) survey, 4) seismic refraction survey, 5) seismic cross-hole tomography survey, and 6) high frequency impedance (ZHF) survey. Each of geophysical surveys were analyzed and joint analyses between geophysical surveys were also performed to deduce the more reliable subsurface information of Dam by using the features and characteristics of each geophysical survey. Since many defects, such as gravel and weathered rock blocks in the dam core, and lots of amounts of leakage, by boring analyses were found, reinforcement by compaction grouting system (CGS) has been conducted in some range of dam. Some geophysical data and data of geotechnical gauges were also used to confirm the effects of reinforcement. Electric resistivity, EM, GPR, ZHF, seismic refraction and seismic tomography surveys show that left side of dam is weak, which means the possibility of existence of gravel, rock block, water and cavities in the core of dam. This result coincides with the boring data. Especially, electric survey after reinforcement shows that even the right side of the dam has been deformed by the strong pressure during the reinforcement itself. As a conclusion, some problems in the dam found. Especially, the dam near spillway shows the high possibility of leakage. It should be pointed out that only the left side of he dam has not a leakage problem. As a whole, the dam has problems of weakness, because of unsatisfactory construction. It is strongly recommended that highly intensive monitoring is required.

• Parasites, Hosts and Diseases
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• v.54 no.6
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• pp.759-768
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• 2016

Cystic echinococcosis (CE) treatment urgently requires a novel drug. The p38 mitogen-activated protein kinases (MAPKs) are a family of Ser/Thr protein kinases, but still have to be characterized in Echinococcus granulosus. We identified a 1,107 bp cDNA encoding a 368 amino acid MAPK protein (Egp38) in E. granulosus. Egp38 exhibits 2 distinguishing features of p38-like kinases: a highly conserved T-X-Y motif and an activation loop segment. Structural homology modeling indicated a conserved structure among Egp38, EmMPK2, and H. sapiens $p38{\alpha}$, implying a common binding mechanism for the ligand domain and downstream signal transduction processing similar to that described for $p38{\alpha}$. Egp38 and its phosphorylated form are expressed in the E. granulosus larval stages vesicle and protoscolices during intermediate host infection of an intermediate host. Treatment of in vitro cultivated protoscolices with the p38-MAPK inhibitor ML3403 effectively suppressed Egp38 activity and led to significant protoscolices death within 5 days. Treatment of in vitro-cultivated protoscolices with $TGF-{\beta}1$ effectively induced Egp38 phosphorylation. In summary, the MAPK, Egp38, was identified in E. granulosus, as an anti-CE drug target and participates in the interplay between the host and E. granulosus via human $TGF-{\beta}1$.

• Korean Journal of Optics and Photonics
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• v.10 no.6
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• pp.500-506
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• 1999

We designed and fabricated a bidirectional optical transceiver module for low cost access network. An integrated chip forming a pin-PD on an 1.3 urn FP-LD was assembled by flip-chip bonding on a Si optical bench, a single mode fiber with an angled end facet was aligned passively with the integrated chip on V-groove of Si-optical bench. Gaussian beam theory was applied to evaluate the coupling coefficients as a function of some parameters such as alignment distance, angle of fiber end facet, vertical alignment error. The theory is also used to search the bottle-neck between transmittance and receiving coupling efficiency in the bi-directional optical system. Tn this paper, we confirmed that reduction of coupling efficiency by the vertical alignment error between laser beam and fiber core axis can be compensated by controlling the fiber facet angle. In the fabrication of sub-module, a'||'&'||' we made such that the fiber facet have a corn shape with an angled facet only core part, the reflection of transmitted laser beam from the fiber facet could be minimized below -35 dE in alignment distance of 2: 30 /J.m. In the same condition, transmitted output power of -12.1 dEm and responsivity of 0.2. AIW were obtained.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1309-1317
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• 2013

There are various parameter estimation methods for the generalized exponential distribution under progressive type I interval censoring. Chen and Lio (2010) studied the parameter estimation method by the maximum likelihood estimation method, mid-point approximation method, expectation maximization algorithm and methods of moments. Among those, mid-point approximation method has the smallest mean square error in the generalized exponential distribution under progressive type I interval censoring. However, this method is difficult to derive closed form of solution for the parameter estimation using by maximum likelihood estimation method. In this paper, we propose two type of approximate maximum likelihood estimate to solve that problem. The simulation results show the obtained estimators have good performance in the sense of the mean square error. And proposed method derive closed form of solution for the parameter estimation from the generalized exponential distribution under progressive type I interval censoring.

• Progress in Medical Physics
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• v.10 no.1
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• pp.41-46
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• 1999

There is necessity for making a smaller and more sensitive detector in small field sizes. This report assesses the suitability of metal-loaded thermoluminescent dosimeters for this purpose. Measurements were performed in the 6 MV photon and 6 MeV electron beams of a medical linear accelerator with LiF thermoluminescence dosimeters (TLD-100) embedded in solid water phantom. TLD-100 chips(surface area 3.2 $\times$ 3.2 $\textrm{mm}^2$) loaded with a metal plate(Tin or gold respectively) were used to enhance dose readings to TLD-100. Surface dose was measured for field size 10 $\times$ 10 $\textrm{cm}^2$ and 100 em SSD. Measurements have been made of the enhanced signal intensity and good linearity for absorbed dose with each metal. Using a 1 mm each metal on TLD-l00 in the beam increased the surface dose to 14% and 56% respectively for 6MV photon. In the case of 6 MeV electron, gold plate enhanced the TL response to 13%, but there is no difference for tin plate. The specific dose response of TLD-100 with thin metal plate increases with electron concentration of metal film, this is most likely due to increased electron scattered from the additional material with electron density higher than TLD-100. This emphasizes the role of TL dosimeters with metal as amplified dosimeters for therapeutic high energy x-ray beams. Due to the enhanced dose reading of TLD-100 with metal plate, it could be possible to develop smaller TL dosimeter with high sensitivity.