• Journal of the Korean Physical Society
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• v.73 no.9
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• pp.1393-1398
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• 2018

In conventional single-photon emission computed tomography (SPECT), only the photoelectric events in the detectors are used for image reconstruction. However, if the $^{131}I$ isotope, which emits high-energy radiations (364, 637, and 723 keV), is used in nuclear medicine, both photoelectric and Compton scattering events can be used for image reconstruction. The purpose of our work is to perform simulations for Compton SPECT by using the Geant4 application for tomographic emission (GATE). The performance of Compton SPECT is evaluated and compared with that of conventional SPECT. The Compton SPECT unit has an area of $12cm{\times}12cm$ with four gantry heads. Each head is composed of a 2-cm tungsten collimator and a $40{\times}40$ array of CdZnTe (CZT) crystals with a $3{\times}3mm^2$ area and a 6-mm thickness. Compton SPECT can use not only the photoelectric effect but also the Compton scattering effect for image reconstruction. The correct sequential order of the interactions used for image reconstruction is determined using the angular resolution measurement (ARM) method and the energies deposited in each detector. In all the results of simulations using spherical volume sources of various diameters, the reconstructed images of Compton SPECT show higher signal-to-noise ratios (SNRs) without degradation of the image resolution when compared to those of conventional SPECT because the effective count for image reconstruction is higher. For a Derenzo-like phantom, the reconstructed images for different modalities are compared by visual inspection and by using their projected histograms in the X-direction of the reconstructed images.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.983-990
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• 2004

Multiple-count problem is occurred when rectangle objects span across several buckets. The CD histogram is a technique which selves this problem by keeping four sub-histograms corresponding to the four points of rectangle. Although It provides exact results with constant response time, there is still a considerable issue. Since it is based on a query window which aligns with a given grid, a number of errors nay be occurred when it is applied to real applications. In this paper, we propose selectivity estimation techniques using the generalized cumulative density histogram based on two probabilistic models : \circled1 probabilistic model which considers the query window area ratio, \circled2 probabilistic model which considers intersection area between a given grid and objects. Our method has the capability of eliminating an impact of the restriction on query window which the existing cumulative density histogram has. We experimented with real datasets to evaluate the proposed methods. Experimental results show that the proposed technique is superior to the existing selectivity estimation techniques. Furthermore, selectivity estimation technique based on probabilistic model considering the intersection area is very accurate(less than 5% errors) at 20% query window. The proposed techniques can be used to accurately quantify the selectivity of the spatial range query on rectangle objects.

• Tuberculosis and Respiratory Diseases
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• v.39 no.6
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• pp.453-473
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• 1992

Background: National survey was performed to estimate the incidence of sarcoidosis in Korea. The clinical data of confirmed cases were analysed for the practice of primary care physicians and pulmonary specialists. Methods: The period of study was from January 1991 to December 1992. Data were retrospectively collected by correspondence with physicians in departments of internal medicine, dermatology, ophthalmology and neurology of the hospitals having more than 100 beds using returning postcards. In confirmed and suspicious cases of sardoidosis, case record chart for clinical and laboratory findings were obtained in detail. Results: 1) Postcards were sent to 523 departments in 213 hospitals. Internal medicine composed 41%, dermatology 20%, ophthalmology 20% and neurology 19%. 2) Postcards were returned from 241 departments (replying rates was 48%). 3) There were 113 confirmed cases from 50 departments and 10 cases. The cases were composed from internal medicine (81%), dermatology (13%), ophthalmology (3%) and neurology (3%). 78 confirmed cases were analysed, which were composed from department of internal medicine (92%), dermatology (5%), and neurology (3%). 4) The time span for analysed cases was 1980 to 1992. one case was analysed in 1980 and the number gradually increased to 18 cases in 1991. 5) The majority of patients (84.4%) were in the age group of 20 to 49 years. 6) The ratio of male to female was 1 : 1.5. 7) The most common chief complains were respiratory symptoms, dermatologic symptoms, generalized discomforts, visual changes, arthralgia, abdominal pains, and swallowing difficulties in order. 16% of the patients were asymptomatic. 8) Mean duration between symptom onset and diagnosis was 2 months. 9) The most common symptoms were respiratory, general, dermatologic, ophthalmologic, neurologic and cardiac origin in order. 10) Hemoglobin, hematocrits and platelet were in normal range. 58% of the patients had lymphopenia measuring less than 30% of white cell count. The ratio of CD4 to CD8 lymphocytes was $1.73{\pm}1.16$ with range of 0.43 to 4.62. ESR was elevated in 43% of the cases. 11) Blood chemistry was normal in most cases. Serum angiotensin converting enzyme (S-ACE) was $66.8{\pm}58.6\;U/L$ with the range of 8.79 to 265 U /L. Proteinuria of more than 150 mg was found in 42. 9% of the patients. 12) Serum IgG was elevated in 43.5%, IgA in 45.5%, IgM in 59.1% and IgE in 46.7%. The levels of complement C3 and C4 were in the normal range. Anti-nuclear antibody was detected in 11% of the cases. Kweim test was performed in 3 cases, and in all cases the result was positive. 13) FVC was decreased in 17.3%, FEV1 in 11.5%, FEV1/FVC in 10%, TLC in 15.2%, and DLco in 64.7%. 14) PaO2 was decreased below 90 mmHg in 48.6% and PaCO2 was increased above 45 mmHg in 5.7%. 15) The percentage of macrophages in BAL fluid was $51.4{\pm}19.2%$, lymphocytes $44.4{\pm}21.1%$, and the ratio of CD4 to CD8 lymphocytes was $3.41{\pm}2.07$. 16) There was no difference in laboratory findings between male and female. 17) Hilar enlargement on chest PA was present in 87.9% (bilaterally in 78.8% and unilaterally in 9.1%). 18) According to Siltzbach's classification, stage 0 was 5%, stage 158.3%, stage 228.3%, and stage 38.3%. 19) Hilart enlargement on chest CT was present in 92.6% (bilaterally 76.4% and unilaterally in 16.2%). 20) HRCT was done in 16 cases. The most common findings were nodules, interlobular thickening, focal patchy infiltrations in order. Two cases was normal finding. 21) Other radiologic examinations showed bone change in one case and splenomegaly in two cases. 22) Gallium scan was done in 12 cases. Radioactivity was increased in hilar and mediastinal lymph nodes in 8 cases and in parenchyme in 2 cases. 23) The pathologic diagnosis was commonly performed by transbrochial lung biopsy (TBLB, 47.3%), skin and mediastinal lymph nodes biopsy (34.5%), peripheral lymph nodes biopsy (23.6%), open lung biopsy (18.2%) and bronchial biopsy in order. 24) The most common findings in pathology were non·caseating granuloma (100%), multi-nucleated giant cell (47.3%), hyalinized acellular scar (34.5%), reticulin fibrin network (20%), inclusion body (10.9%), necrosis (9.1%), and lymphangitic distribution of granuloma (1.8%) in order. Conclusion: Clinical, laboratory, radiologic and pathologic findings were summarized. This collected data will assist in finding a test for detection and staging of sarcoidosis in Korea in near future.

• The Journal of Korean Society of Virology
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• v.29 no.4
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• pp.271-281
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• 1999

The nested polymerase chain reaction (PCR) assay was used to determine the sequences of reverse transcriptase (RT) codons 41, 67, 70, 210, 215 and 219 of human immunodeficiency virus-1 (HIV-1) pol gene. Template DNA was obtained from uncultured peripheral blood mononuclear cells from 27 Korean HIV-1 infected patients treated with ZDV and Korean red ginseng. The second PCRs were done for 2 separated regions (RT codons $13{\sim}98$ and $152{\sim}259$) with $5\;{\mu}l$ of the first PCR productNucleotide sequences were determined by direct sequencing. In the 27 patients, CD4+ cell count decreased from $230{\pm}117/{\mu}l$ to $152{\pm}162/{\mu}l$ for $46{\pm}26$ months (Mo), and actual duration of ZDV intake was $72{\pm}16$ Mo. In the 16 patients who had been treated with ZDV therapy ${\ge}25$ Mo, the incidences of 70R, 215F/Y, and 41L were 61%, 28% and 22%, respectively and those of 67N, 210W and 219Q were 17%. The incidences of 215F/Y were 6.7% for group ${\le}12$ Mo treatment, 22.7% for group with 13 to 24 Mo, and 27.8% for group ${\ge}25$ Mo. There was no mutation in 9 patients. It might be associated with the interruption of ZDV therapy for more than 6 months in 6 patients. This study shows that the detection of mutation could be useful prognostic marker with other clinical and virological data, and very low mutation rate is dectected compared to overseas reports.

• Tuberculosis and Respiratory Diseases
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• v.68 no.2
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• pp.97-100
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• 2010

A 73-year-old man was admitted with a sudden onset of dyspnea. He had never smoked. The chest radiograph and computed tomography revealed bilateral ground glass opacity and an enlarging perihilar consolidation with lymphadenopathies. There was a higher percentage of eosinophils (72%) in the bronchoalveolar lavage fluid (BALF) than normal. The patient was diagnosed with acute eosinophilic pneumonia and managed with steroid. Pneumocystis pneumonia (PCP) was diagnosed by an examination of the BALF, and the patient was treated with trimethoprim-sulphamethoxazole. The patient tested positive to the HIV antibody and the peripheral blood CD-4 positive lymphocyte count was only $33/{\mu}L$. The percentage of eosinophils in the BALF can increase in some cases of PCP that is complicated with AIDS. Only a few cases of eosinophilic pneumonia associated with PCP pneumonia have been reported in patients with AIDS but there are no case reports in Korea. This case highlights the need to consider PCP when the percentage of eosinophils in the BALF is elevated.

• Journal of Chest Surgery
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• v.37 no.2
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• pp.131-138
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• 2004

High-flow gas insufflation to get a bloodless field during off-pump coronary artery bypass may have adverse effects on the coronary endothelium. This study was designed (1) to elucidate the effect of carbon dioxide gas insufflations on the coronary endothelium at different flow rates and (2) to assess the protective effect of humidifcation against the coronary endothelial damage. Material and Method: In nine pigs, the left anterior descending coronary artery (LAD) was exposed after a median sternotomy. The LAD was divided into 4 segments and a coronary arteriotomy was made in each LAD segment in the beating heart. The far distal arteriotomy was exposed to room air for 10 minutes and was harvested as a control. Non-humidified carbon dioxide gas at a continuous flow rate of 5 L/min (Group I), humidified carbon dioxide gas at a continuous flow rate of 5 L/min (Group II), and humidified carbon dioxide gas at a continuous flow rate of 10 L/min (Group III) were insufflated for 10 minutes on each coronary arteriotomy site, respectively. After harvesting the coronary segments, hematoxylin-eosin staining, elastic fiber staining, and immunostaining with a CD34 monoclonal antibody were performed to evaluate the depth of endothelial damage and to count the residual endothelial cells, Result: In all three groups (Group I, II, and III), internal elastic laminae were preserved, however, the endothelial layers were significantly damaged by carbon dioxide gas insufflation. The mean percentages of remaining endothelial cells were 20,9$\pm$16.7%, 39.3$\pm$19.6%, and 6.8$\pm$5.3%, in groups I, II, and III, respectively. The percentages of remaining cells were significantly higher in group II than in groups I and III (p=0.008). The percentages of remaining cells were significantly higher in group I than in group III (p=0.008). Conclusions: The harmful effect of carbon dioxide gas insufflation on the coronary endothelium was dependent on the flow rate. The addition of humidification did not protect the coronary endothelium from denudation injury caused by high flow carbon dioxide gas insufflations.

• Tuberculosis and Respiratory Diseases
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• v.43 no.1
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• pp.75-87
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• 1996

Background: Lung cancer is the second most frequent malignancy in man in Korea. Surgery is the best treatment modality for non-small cell lung cancer, but most patients were presented in far advanced stage. So radiation therapy(RT) with or without chemotherapy is the next choice and radiation-induced pneumonitis and pulmonary fibrosis is the major limiting factor for the curative RT. Radiation pneumonitis is manifested with fever, cough and dyspnea, 2~3 months after the termination of radiotherpy. Chest X ray shows infiltration, typically limited to the radiation field, but occasionally bilateral infiltration was reported. Also Gibson et al reported that BAL lymphocytosis was found in both lungs, even though the radiation was confined to one lung. The aim of this study is to investigate the change of adhesion molecules expression on BAL cells and serum soluble ICAM-1(sICAM-1) level after the RT and its relationship to the development of radiation pneumonitis. The second aim is to confirm the bilaterality of change of BAL cell pattern and adhesion molecule expression. Subjects: BAL and the measurement of sICAM level in serum and BALF were done on 29 patients with lung cancer who received RT with curative intention. The BAL was done before the RT in 16 patients and 1~2 month after RT in 18 patients. 5 patients performed BAL before and after RT. Result: Clinically significant radiation pneumonitis developed in 7 patients. After RT, total cell count in BAL was significantly increased from $(20.2{\pm}10.2){\times}10^6\;cells/ml$ to $(35.3{\pm}21.6){\times}10^6\;cells/ml$ (p=0.0344) and %lymphocyte was also increased from $5.3{\pm}4.2%$ to $39.6{\pm}23.4%$ (p=0.0001) in all patient group. There was no difference between ipsilateral and contraleteral side to RT, and between the patients with and without radiation-pneumonitis. In whole patient group, the level of sICAM-1 showed no significant change after RT(in serum: $378{\pm}148$, $411{\pm}150\;ng/ml$, BALF: $20.2{\pm}12.2$, $45.1{\pm}34.8\;ng/ml$, respectively), but there was a significant difference between the patients with pneumonitis and without pneumonitis (serum: $505{\pm}164$ vs $345{\pm}102\;ng/ml$, p=0.0253, BALF: $67.9{\pm}36.3$ vs $25.2{\pm}17.9\;ng/ml$, p=0.0112). The expression of ICAM-1 on alveolar macrophages (AM) tends to increase after RT (RMFI: from $1.28{\pm}0.479$ to $1.63{\pm}0.539$, p=0.0605), but it was significantly high in patients with pneumonitis ($2.10{\pm}0.390$) compared to the patients without pneumonitis ($1.28{\pm}0.31$, p=0.0002). ICAM-1 expression on lymphocytes and CD 18 (${\beta}2$-integrin) expression tended to be high in the patients with pneumonitis but the difference was statiastically not significant. Conclusion: Subclinical alveolitis on the basis of BAL finding developed bilaterally in all patients after RT. But clinically significant pneumonitis occurred in much smaller fraction and the ICAM-1 expression on AM and the sICAM-1 level in serum were good indicator of it.

• Korean journal of food and cookery science
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• v.24 no.1
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• pp.68-75
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• 2008

The aim of this study was to evaluate the quality characteristics and antioxidant activity of yogurt containing spirulina. Yogurt base was prepared from skim milk added with $0.25{\sim}1%(w/v)$ spirulina powder and fermented with lactic acid bacteria (S. thermophilus : L. bulgaricus = 1 : 1) at $40^{\circ}C$ for 12 hr. Kiwi puree and oligosaccharides were then added. The addition of 1% spirulina powder stimulated the growth of lactic acid bacteria, which showed the highest viable cell count ($3.4{\times}10^9$ CFU/mL), and increased the titratable acidity (1.10%). The viscosity range of the yogurt was 6,000 to 9,000 cP, and the sugar content of the yogurt was around 18 $^{\circ}Brix$. The antioxidant activities were determined using the DPPH method, and the hydroxyl radical scavenging activity of the yogurt containing spirulina was higher than that of the control. The sensory evaluation scores for appearance, odor, taste, overall acceptability and buying intention were higher in the yogurt containing 0.25% spirulina than in the other groups. The amount of macronutrients in the yogurt containing spirulina was higher than that in the control. In addition, the amounts of micronutrients in the yogurt containing spirulina was significantly increased. According to these results, the optimum concentration of spirulina powder is around 0.25%.