• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.98-104
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• 1995

Recently murine monoclonal antibodies have been studied actively for radioimmuno-scintigraphy and radioimmunotherapy, especially on patients with leukemia and lymphoma. In this research, we studied radiolabeling and immunologic characteristics of two in-house anti-leukemic monoclonal antibodies(anti-CALLA & anti-JL-1 antibodies) to make the basis for their clinical application. Each antibody was radiolabeled successfully with $^{99m}Tc$ by pretargeting transchelation method and with $^{125}I$ by lodogen method. We also studied cell binding assay, Scatchard analysis and modulation phenomenon. $^{125}I$ showed 90% labeling efficiency for each anti-body which was satisfactory, but $^{99m}Tc$ showed labeling efficiency below 70%, for which we need better labeling method. In cell binding assay, the immunoreactivity(IR) was low for $^{99m}Tc$-labeled antibodies. Scatchard analysis showed satisfactory data for both binding affinity. The affinity constant and antibody binding sites per cell are around $10^9M^{-1}$ and $10^4$, respectively. There was no modulation phenomenon in cases of $^{125}I$ or $^{99m}Tc$ labeled antibodies. We expect that two anti-leukemic monoclonal antibodies may be useful in diagnosis and therapy for leukemia and lymphoma patients.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.270-271
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• 2005

A high Tc superconducting with a nominal composition of $Bi_2Sr_2Ca_2Cu_3O_Y$ was prepared by the citarte method. The solid precursor produced by the dehydration of the gel at $120^{\circ}C$ for 12h is not in the amorphous state as expected but in a crystalline state. X-ray diffraction peaks of nearly the same angular position as the peaks of high Tc phase were observed in the precursor. After pyrolysis at $400^{\circ}C$ and calcination at $840^{\circ}C$ for 4h, the (001)peak of the high Tc phase was cleary observed. Experimental results suggest that the intermediate phase formed before the formation of the superconducting phase may be the most important factro in determining whether it is easy to form the high Tc phase or not. because the nucleation barriers of the two superconducting phase may be altered by the variation of the crystal structures of those intermediate phase.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.3
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• pp.311-320
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• 1999

This study conducts to analyze comparative accuracy when both Image Transformation Methods and Supervised Classifications on multi-spectral TM using a case of Lower Tumen River Area. In terms of overall classification accuracy, maximum likelihood method turns out higher than other one, but in a case of vegetation only, MNF and TC image transformation methods produce a better quality of the result. Especially, seven dimensional images including MNF, TC, and NDVI create better image than three dimensional one. Among these transformation methods, maximum likelihood method results out the best one. Multi-spectral image could be useful as an important basic material for site selection of industrial allocation as well as Tumen River Area Economic Development Plan.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.22-30
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• 1995

To predict preoperatively the safety of permanent occlusion of an internal carotid artery with $^{99m}Tc$-HMPAO brain single photon emission computed tomography(SPECT) from an objective point of view, Twenty-four patients underwent balloon test occlusion (BTO) of the internal carotid arteries because of neck and skull base tumors. The authors assessed the uptake of both middle cerebral artery territories before and during BTO with $^{99m}Tc$-HMPAO brain SPECT using semiquantitative analysis method and compared the results with other factors(neurologic examination, arterial stump pressure and electroenceph-alogram). Nineteen patients had not experienced neurological deteriorating or any problem during BTO. Their comparative uptakes of the middle cerebral artery territories were 95 to 101% of the pre-BTO state. The remaining five patients showed severe neurologic symptoms such as transient hemiplegia and unconsciousness. Their comparative uptake of the middle cerebral artery territories were 77 to 85% of the pre-BTO state, and were well matched with other factors. $^{99m}Tc$-HMPAO brain SPECT before and during BTO seems to be a simple and objective method for prediction of permanent neurologic deficits when the comparative uptake of middle cerebral artery territories during BTO is lower than 85% of that before BTO.

• The Korean Journal of Nuclear Medicine
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• v.25 no.2
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• pp.227-236
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• 1991

Background: The evaluation of individual renal function is important to diagnosis and follow-up of various diseases. Ureteral catheterization of each kidney has been widely used for this purpose, but this method had some technical difficulty, frequent complications and much restriction in reapplication. Therefore we tried to applicate radiopharmaceuticals for the evaluation of individual renal function. Methods: We measured 2 hour, 4 hour and 24 hour relative renal uptake of $^{99m}Tc-DMSA$ and relative glomerular filteration rate of $^{99m}Tc-DTPA$ with 59 patients with various renal diseases to determine their usefulness for assessment of individual renal function and to compare correlations between every renal uptake of $^{99m}Tc-DMSA$ and relative glomerular filteration rate. Results: The correlations between 2 hour-, 4 hour- and 24 hour- relative renal uptake of $^{99m}Tc-DMSA$ and relative glomerular filteration rate of $^{99m}Tc-DTPA$ were R=0.9190 (p < 0.001), R: 0.9229 (p<0.001) and R=0.9917 (p<0.001). In acute obstructive uropathy, the correlations at 2 hour and 4 houre were poor as R=0.1812 (p<0.05) and R=0.4923 (p < 0.05), but the correlation at 24 hour was good as R=0.9942 (p<0.001). Conclusions: We concluded that relative renal uptake at 2 hour and 4 hour had good correlation with relative DTPA uptake ratio in the cases without chronic renal failure and obstructive uropathy. Delayed image with 24 hour relative renal uptake $^{99m}Tc-DTPA$ had the best correlation with relative glomerular filteration rate of $^{99m}Tc-DTPA$ and that might be useful in evaluation of chronic renal disease in which showed increased beckground activity or acute obstructive uropathy.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.1
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• pp.39-43
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• 2008

Purpose: There are various methods to diagnose hemangioma, such as ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI) and nuclear medicine. However, by development of SPECT imaging, the blood-pool scan using $^{99m}Tc$-labeled red blood cell has been used, because it was non-invasive and the most economical method. Therefore, in this study, we proposed that the usefulness of $^{99m}Tc$-RBC scan and SPECT of the head and neck to diagnose unlocated hemangiomas. Materials and Methods: $^{99m}Tc$-RBC scan and SPECT was performed on 6 patients with doubtful hemangioma (4 person, head; 1 person, neck; 1 person, another). We labeled radiopharmaceutical using modified in vivo method and then, centrifuged it to remove plasma. After a bolus injection of tracer, dynamic perfusion flow images were acquired. Then, anterior, posterior, both lateral static blood-pool images were obtained as early and 4 hours delayed. SPECT was progressed 64 projections per 30 seconds. Each image was interpreted by physicians, Nuclear medicine specialist, and technologist blinded to patient's data. Results: In 5 patients of all the radioactivity of doubtful site didn't change in flow images, but, in blood-pool, delayed and SPECT images, it was increased. So, it was a typical hemangioma finding. The size of lesion was over 2 cm, and it could discriminate as comparing to the delayed and SPECT imaging. On the other hand, in 1 patient, the radioactivity was increased in blood-pool images, but, not in delayed and SPECT images, so, it was proved no hemangioma. Conclusion: Using $^{99m}Tc$-RBC Scan and SPECT, we could diagnose the hemangiomas in head and neck, as well as, liver, more non-invasive, economical, and easy. Therefore, it considered that $^{99m}Tc$-RBC scan and SPECT would offer more useful information for diagnosis of hemangioma, rather than otherimaging such as US, CT, MRI.

• Journal of Acupuncture Research
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• v.17 no.2
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• pp.247-259
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• 2000

Objective : The mechanism of acupuncture to increase cerebral blood flow is still uncertain. The purpose of this study was to evaluate the neural basis of acupuncture by comparing the cerebral regions activated by the stimulation of two different methods of acupunctures at the same acupoint which was suggested by oriental medicine to increase rCBF. Materials and Methods : Thirty-nine healthy volunteers(26 males, 13 females, age $31{\pm}11$ years) were studies by rest/acupuncture Tc-99m ECD brain SPECT using a subtraction method. SPECTs using two methods(needle retention and heated needle with 90% alcohol) at two acupoints (right LI. 4 and ST. 36) were peformed at an interval of three days. For the needle retention method, acupuncture needle was inserted to a depth of about 2 cm into each acupoint 8 minutes after the lst acquisition and continued to retain, and the second injection of Tc-99m ECD was done 15 minutes after the insertion of needle. For the heated acupuncture method, heated needle was inserted in a twinkle within several msec 20 second after the second injection of Tc-99m ECD. The differences of between rest and acupuncture activation state were statistically analyzed using a statistical parametric mapping software. Result : Acupunctures of both methods reveal similar patterns of increase in rCBF. Acupuncture at ST.36 increase rGBF in left anterior temporal, right inferior frontal lobes, and left cerebellum. Acupuncture at LI. 4 increase rCBF in the left frontal cortex, right temporal pole, both inferior frontal cortices and right cerebellum. Conclusion : The effects of two different acupunctures to the same acupoints on rCBF were similar. Therefore, this result suggests Chat the mechanism of acupuncture in the increase of cerebral blood flow have a neural basis.

• Tribology and Lubricants
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• v.34 no.5
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• pp.169-174
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• 2018

A multi-stage compressor (MSC) is comprised of several impellers installed in the pinion gear shaft driven by a main bull gear. In the pinion shaft, a thrust collar (TC) is installed to support the thrust load. The TC makes the lubrication system simpler in the MSC; therefore, it is widely used in similar kinds of machinery. Typically, TCs are installed on both sides of the bull gear and pressure is developed in the lubricated area by creating a taper angle on the TC and bull gear surface. In the current study, we developed a numerical analysis model to evaluate the performance of the TC considering its design parameters. We sloved the Reynolds equation using the finite element method and applied the half Sommerfeld condition to consider cavitation. Based on the pressure calculated in the lubricated area, we calculated the power loss and minimum film thickness. In addition, we calculated stiffness and damping using perturbation method. We performed parametric studies using the developed model. The results of the analysis show that the maximum pressure presents in the center area of the TC and it increases with the taper angle. The area over which pressure is developed decreases with the taper angle. The results also show that there is an optimum taper angle providing minimum power loss and maximum film thickness. Additionally, the stiffness and damping decrease with the taper angle. As the applied load increases, the power loss increases and the minimum film thickness decreases. However, the stiffness and damping increase with the applied load.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.124-129
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• 1998

The ultrasonic pulse measurements can be used to detect the development of cracks in concrete structures and to check deterioration due to frost or chemical action. An estimate of the depth of a visible crack at the surface can be obtained by measuring the transit times that across the crack for two different arrangements of the transducers placed on the surface. In this paper, the concrete cracks that artificially introduced crack of width 1, 2mm and depth 20, 40, 60, 80mm were measured by Tc-To, Direct and Indirect Method. The test results indicate that the Tc-To Method is the most useful in measuring crack of concrete structures. And the crack depth calculated by the Direct and Indirect Method is shown bigger than artificially introduced real crack depth.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.65-71
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• 2011

Purpose: The recently adopted multiple confocal SPECT SYSTEM (hereinafter called IQ SPECT$^{TM}$) has a high difference from the conventional myocardial perfusion SPECT in the collimator form, image capture method, and image reconstruction method. This study was conducted to compare this novice equipment with the conventional one to design a protocol meeting the IQ SPECT, and also determine the characteristics and usefulness of IQ SPECT. Materials and Methods: 1. For the objects of LEHR (Low energy high resolution) collimator and Multiple confocal collimator, $^{99m}Tc$ 37MBq was put in the acrylic dish then each sensitivity ($cpm/{\mu}Ci$) was measured at the distance of 5 cm, 10 cm, 20 cm, 30 cm, and 40 cm respectively. 2. Based on the sensitivity measure results, IQ SPECT Protocol was designed according to the conventional general myocardial SPECT, then respectively 278 kBq/mL, 7.4 kBq/mL, and 48 kBq/mL of $^{99m}Tc$ were injected into the myocardial and soft tissues and liver site by using the anthropomorphic torso phantom then the myocardial perfusion SPECT was run. 3. For the comparison of FWHMs (Full Width at Half Maximum) resulted from the image reconstruction of LEHR collimator, the FWHMs (mm) were measured with only algorithms changed, in the case of the FBP (Filtered Back projection) method- a reconstruction method of conventional myocardial perfusion SPECT, and the 3D OSEM (Ordered subsets expectation maximization) method of IQ SPECT, by using $^{99m}Tc$ Line source. Results: 1. The values of IQ SPECT collimator sensitivity ($cpm/{\mu}Ci$) were 302, 382, 655, 816, 1178, and those of LEHR collimator were measured as 204, 204, 202, 201, 198, both at the distance of 5 cm, 10 cm, 20 cm, 30 cm, and 40 cm respectively. It was found the difference of sensitivity increases up to 4 times at the distance of 30 cm in the cases of IQ SPECT and LEHR. 2. The myocardial perfusion SPECT Protocol was designed according to the geometric characteristics of IQ SPECT based on the sensitivity results, then the phantom test for the aforesaid protocol was conducted. As a result, it was found the examination time can be reduced 1/4 compared to the past. 3. In the comparison of FWHMs according to the reconstructed algorithm in the FBP method and 3D OSEM method followed after the SEPCT test using a LEHR collimator, the result was obtained that FWHM rose around twice in the 3D OSEM method. Conclusion : The IQ SPECT uses the Multiple confocal collimator for the myocardial perfusion SPECT to enhance the sensitivity and also reduces examination time and contributes to improvement of visual screen quality through the myocardial-specific geometric image capture method and image reconstruction method. Due to such benefits, it is expected patients will receive more comfortable and more accurate examinations and it is considered a further study is required using additional clinical materials.