• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.2
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• pp.164-170
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• 2004

Liquid Injection Nozzle(LIN) tube and Calandria tube(CT) in pressurized Heavy Water Reactor (PHWR) are .ross-aligned horizontally. These neighboring tubes can contact each other due to the sag of the calandria tube resulting from the irradiation creep and thermal creep, and fuel load, etc. In order to judge the contact which might be the safety concern, the remote field eddy current (RFEC) technology is applied for the gap measurement in this paper. LIN can be detected by inserting the RFEC probe into pressure tube (PT) at the crossing point directly. To obtain the optimal conditions of the RFEC inspection, the sensitivity, penetration and noise signals are considered simultaneously. The optimal frequency and coil spacing are 1kHz and 200mm respectively. Possible noises during LIN signal acquisition are caused by lift-off, PT thickness variation, and gap variation between PT and CT. The simulated noise signals were investigated by the Volume Integral Method(VIM). Signal analysis on the voltage plane describes the amplitude and shape of LIN and possible defects at several frequencies. All the RFEC measurements in the laboratory were done in variance with the CT/LIN gap and showed the relationship between the LIN gap and the signal parameters by analyzing the voltage plane signals.

• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.76-82
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• 2006

Fenton's reaction are difficult to apply in the field due to the low pH requirements for the reaction and the loss of reactivity caused by the precipitation of iron (II) at neutral pH. Moreover, Fenton-like reactions using iron mineral instead of injection of iron ion as a catalyst are operated to get high removal result at low pH. Because hydroxyl radical can generate at the surface of iron mineral, there are competition with a lot of hydroxide at around neutral pH. On the other side, to operate Fenton's reaction series at neutral pH, modified Fenton reaction is suggested. The complexes, composed by iron ions (ferrous ion or ferric ion)-chelating agent, could be acted as a catalyst and presented in the solution at neutral pH. However, modified Fenton reaction requires a lot of hydrogen peroxide. Accordingly, the purpose of this experiment was to effectively combine Fenton-like reaction and modified Fenton reaction for extending application of Fenton's reaction. i.e., injecting chelating agents in Fenton-like reaction at around neutral pH is increasing the concentration of dissolved iron ion and highly promoting the oxidation effect. 2,4,6-trinitrotoluene (TNT) was used as a probe compound for comparing reaction efficiencies in this study. If the concentration of dissolved iron ion in combined Fenton process were existed more than 0.1 mM, the total TNT removal were increased. Magnetite-NTA system showed the best TNT removal (76%) and Magnetite-EDTA system indicated about 56% of TNT removal. The results of these experiments proved more promoted 40-60% of TNT removal than Fenton-like reaction's.

• Korean Journal of Bronchoesophagology
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• v.16 no.2
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• pp.109-114
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• 2010

Background: The aim of this study was to compare a novel mannose receptor-binding agent(Technetium-99m human serum albumin, $^{99m}Tc$-MSA) with $^{99m}Tc$-phytate for sentinel node mapping in patients with esophageal cancer. Material and Method: Twenty patients with clinical stage T1N0m0 or T2N0M0 esophageal cancer that were candidates for esophagectomy were enrolled. Endoscopic injection of $^{99m}Tc$-MSA or $^{99m}Tc$-phytate was administered at the peri-tumor region before surgery in 10 patients. The radioactive lymph nodes were identified with a handheld gamma probe after lymph node dissection. Results: The patient's age and the sex ratio of both groups were similar. The clinical stage, tumor location, and operative technique did not differ. The total number of dissected lymph nodes did not differ ($28.5{\pm}9.12$ in MSA group, $32.2{\pm}11.24$ in phytate group, p=0.430). The sentinel node was identified in all cases in both groups. The number of sentinel nodes per patient was $2.7{\pm}1.57$ in the MSA group, which was significantly greater than the $1.7{\pm}0.88$ in the phytate group (p=0.036). Five out of 20 patients whose sentinel nodes could be identified had metastases; however, neither group had any false-negative results for sentinel node identification. Conclusion: Sentinel nodes were detected more frequently with MSA than with phytate.

• Clinical and Experimental Pediatrics
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• v.52 no.7
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• pp.824-831
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• 2009

Purpose : We aimed to investigate the efficacy of and functional recovery after intracerebral transplantation of different doses of mouse mesenchymal stem cells (mMSCs) in immature rat brain with hypoxic-ischemic encephalopathy (HIE). Methods : Postnatal 7-days-old Sprague-Dawley rats, which had undergone unilateral HI operation, were given stereotaxic intracerebral injections of either vehicle or mMSCs and then tested for locomotory activity in the 2nd, 4th, 6th, and 8th week of the stem cell injection. In the 8th week, Morris water maze test was performed to evaluate the learning and memory dysfunction for a week. Results : In the open field test, no differences were observed in the total distance/the total duration (F=0.412, P=0.745) among the 4 study groups. In the invisible-platform Morris water maze test, significant differences were observed in escape latency (F=380.319, P<0.01) among the 4 groups. The escape latency in the control group significantly differed from that in the high-dose mMSC and/or sham group on training days 2-5 (Scheffe's test, P<0.05) and became prominent with time progression (F=6.034, P<0.01). In spatial probe trial and visible-platform Morris water maze test, no significant improvement was observed in the rats that had undergone transplantation. Conclusion : Although the rats that received a high dose of mMSCs showed significant recovery in the learning-related behavioral test only, our data support that mMSCs may be used as a valuable source to improve outcome in HIE. Further study is necessary to identify the optimal dose that shows maximal efficacy for HIE treatment.

• Tuberculosis and Respiratory Diseases
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• v.41 no.3
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• pp.215-221
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• 1994

Background: It is well known that oxygen free radicals(OFR) play a vital role in the various type of acute lung injury. Among various antioxidant defense mechanisms, the superoxide dismutases(SOD) are thought to be the first line of antioxidant defense by catalyzing the dismutation of two superoxide radicals to yield hydrogen peroxide and oxygen. Eukaryotic cells contain two types of intracellular SOD : cytosolic, dimeric copper/zinc- containing enzyme(CuZnSOD) and mitochondrial, tetrameric manganese-containing enzyme(MnSOD). The purpose of this study is to evaluate the time-dependent gene expression of MnSOD and CuZnSOD in the endotoxin-treated rats, and to compare with the manifestations of LPS-induced acute lung injury in rats. Methods: Total RNA from rat lung was isolated using single step phenol extraction 0, 1, 2, 4, 6, 12, 18, 24 hours after E. coli endotoxin injection(n=3, respectively). RNA was separated by formaldehyde-containing 1.2% agarose gels elctrophoresis, transblotted, baked, prehybridized, and hybridized with $^{32}P$-labeled cDNA probes for rat MnSOD and CuZnSOD, which were kindly donated by Dr. Ho(Duke University, Durham, NC, USA). The probes were labeled by nick translation. Blots were washed and autoradiography were quantitated using laser densitometry. Equivalent amounts of total RNA/gel were assessed by monitoring 28S and 18S rRNA. Results: Endotoxin caused a rise in steady-state MnSOD mRNA levels by 4h with peak mRNA accumulation by 6h. Continued MnSOD mRNA expression was observed at 12h. CuZnSOD mRNA expression was observed from 1h to 24h with peak levels by 18h. Conclusion: These results suggest that SOD palys an important defensive role in the endotoxin-induced acute lung injury in rats.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.1
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• pp.75-79
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• 2019

Purpose Cadmium-zinc-telluride (CZT) camera with semiconductor detector is capable of dynamic myocardial perfusion SPECT for coronary flow reserve (CFR). Image acquisition with the heart positioned within 2 cm in the center of the quality field of view (QFOV) is recommended because the CZT detector based on focused multi-pinhole collimators and is stationary gantry without rotation. The aim of this study was to investigate the optimal method for measuring position of the heart within the center of the QFOV when performing dynamic myocardial perfusion SPECT with the Discovery NM 530c camera. Materials and Methods From June to September 2018, 45 patients were subject to dynamic myocardial perfusion SPECT with D530c. For accurate heart positioning, the patient's heart was scanned with a mobile ultrasound and marked at the top of the probe where the mitral valve (MV) was visible in the parasternal long-axis view (PLAX). And, the marked point on the patient's body matched with the reference point indicated CZT detector in dynamic stress. The heart was positioned to be in the center of the QFOV in rest. The coordinates of dynamic stress and rest were compared statistically. Results The coordinates of the dynamic stress using mobile ultrasound and those taken of the rest were recorded for comparative analysis with regard to the position of the couch and analyzed. There were no statistically significant differences in the coordinates of Table in & out, Table up & down, and Detector in & out (P > 0.05). The difference in distance between the 2 groups was measured at $0.25{\pm}1.00$, $0.24{\pm}0.96$ and $0.25{\pm}0.82cm$ respectively, with no difference greater than 2 cm in all categories. Conclusion The position of the heart taken using mobile ultrasound did not differ significantly from that of the center of the QFOV. Therefore, The use of mobile ultrasound in dynamic stress will help to select the correct position of the heart, which will be effective in clinical diagnosis by minimizing the image quality improvement and the patient's exposure to radiation.

• Journal of the Korean Society of Radiology
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• v.15 no.4
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• pp.463-472
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• 2021

Demand for examinations using transvaginal transducer with high frequencies is increasing to observe pelvic organs in gynecological ultrasound tests. However, the quality control of the replacement probe in clinical trials is not properly implemented and the evaluation criteria have not been established. Therefore, 58 transvaginal transducers and 20 convex transducers were applied to the ATS-539 ultrasound phantom for 20 ultrasound devices currently in clinical use to obtain their respective images and measure them quantitatively and qualitatively. For quantitative measurements, vertical measurement, horizontal measurement, and focal zone and qualitative measurements, dead zone, axial·lateral resolution, sensitivity, functional resolution, gray scale·dynamic range were performed. Quantitative statistical analysis showed significant differences between the two transducers in the lateral measurement and local area (p<0.05). qualitative comparative analysis showed differences in sensitivity and functional resolution. This occurs due to the difference in frequency between transducers and the transducer's injection geometry. Based on the above experiments, the tolerance for horizontal measurement is raised to 10% (±8 mm), the tolerance for sensitivity is observed up to 6 cm deep, which is 12 cm deep,which is the level of the third quartile (75%). The permissible range of functional resolution is up to 6 (12 cm), 6 (12 cm), 11 (11 cm), 9 (9 cm), 6 (6 cm) target, which is the level of the third quartile (75%). It is considered reasonable to adjust the depth of targets in gray scale·dynamic range to measure at a depth of 2 cm, which is 50% of the depth of 4 cm. As above, the criteria for evaluating the quality of transvaginal transducer for use in the past have been proposed and it is expected that this study will be used as a basic data for the production of phantom exclusively for transvaginal transducer in the future.