• Progress in Medical Physics
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• v.26 no.3
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• pp.160-167
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• 2015

Radiation exposure from medical diagnostic imaging procedures to patients is one of the most significant interests in diagnostic x-ray system. A miniature x-ray intraoral tube was developed for the first time in the world which can be inserted into the mouth for imaging. Dose evaluation should be carried out in order to utilize such an imaging device for clinical use. In this study, dose evaluation of the new x-ray unit was performed by 1) using a custom made in vivo Pig phantom, 2) determining exposure condition for the clinical use, and 3) measuring patient dose of the new system. On the basis of DRLs (Diagnostic Reference Level) recommended by KDFA (Korea Food & Drug Administration), the ESD (Entrance Skin Dose) and DAP (Dose Area Product) measurements for the new x-ray imaging device were designed and measured. The maximum voltage and current of the x-ray tubes used in this study were 55 kVp, and 300 mA. The active area of the detector was $72{\times}72mm$ with pixel size of $48{\mu}m$. To obtain the operating condition of the new system, pig jaw phantom images showing major tooth-associated tissues, such as clown, pulp cavity were acquired at 1 frame/sec. Changing the beam currents 20 to $80{\mu}A$, x-ray images of 50 frames were obtained for one beam current with optimum x-ray exposure setting. Pig jaw phantom images were acquired from two commercial x-ray imaging units and compared to the new x-ray device: CS 2100, Carestream Dental LLC and EXARO, HIOSSEN, Inc. Their exposure conditions were 60 kV, 7 mA, and 60 kV, 2 mA, respectively. Comparing the new x-ray device and conventional x-ray imaging units, images of the new x-ray device around teeth and their neighboring tissues turn out to be better in spite of its small x-ray field size. ESD of the new x-ray device was measured 1.369 mGy on the beam condition for the best image quality, 0.051 mAs, which is much less than DRLs recommended by IAEA (International Atomic Energy Agency) and KDFA, both. Its dose distribution in the x-ray field size was observed to be uniform with standard deviation of 5~10 %. DAP of the new x-ray device was $82.4mGy*cm^2$ less than DRL established by KDFA even though its x-ray field size was small. This study shows that the new x-ray imaging device offers better in image quality and lower radiation dose compared to the conventional intraoral units. In additions, methods and know-how for studies in x-ray features could be accumulated from this work.

• 한국초등상담교육학회:학술대회논문집
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• 2004.01a
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• pp.223-245
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• 2004

The purpose of this study was to investigate the differences in depression, irrational faith and the school adaptation of elementary school students by their sex and region, to provide basic materials to teach children with the likelihood to be depressed by analyzing the correlation of depression, irrational faith and school adaptation, and help them to have healthy emotion and behaviors. To achieve these goals, following agenda were set. First, what are the differences in the depression, the irrational faith and the school adaptation of elementary school students by their sex and region? Second, what is the relationship between the depression characteristics and the irrational faith of elementary school students? Third, what is the relationship between the irrational faith and the school adaptation of elementary school students? Fourth, what is the relationship between the depression characteristics and school adaptation of elementary school students? : To resolve these agenda, the subjects were selected from Grade 6 students from the elementary schools locatec in Suwon and Hwaseong. The jubjects were selected from the two schools in Suwon and three schools in Hwaseong which were randomly chosen. The subjects were 670 in total. 70 insincere answers were excluded from the analysis. Therefore the subjects used in the analysis were 600 in total(150 male and female students in city respectively and 150 male and female students in rural area respectively). The tools used for this study were Children's Depression Inventory (CDI), Irrational Faith Test (over-self-reliance, dichotomy, determinism, over-concern, evasive faith, over dependent faith), School Adaptation Test (Attitudes to teachers and school environments, hobbies and specialties, academic achievements, peer relationship). Materials were processed with the SPSS program for ANOVA and correlation analysis. All the statistical values were verified at .05 level. The followings are the results of the analysis of the collected data. First, in the analysis of depression, there was significant difference between male and female students (F=4.75, p<.05). Female students (X =56.93) showed a little higher value than male students (X =53.83). There was significant difference between regions (F=13.02, p<.001), too. Rural area students (X =57.93) showed higher value than city area students (X =52.82). When analyzing irrational faith, there was significant difference between male and female students (F=S.60, p<.05). Female students (X =81.32) showed a little higher value than male students (X =77.72). There was no significant difference according to regions. When analyzing the school adaptation, there was no significant difference according to either sex or region. Second, depression and irrational faith showed highly positive correlations in all areas. In particular, over concern and evasive faith showed the highest correlation with depression inclination (r=.68, p<.001). When looking into the results by sex and by region, female students (r=.70, p<.001) and the rural area students (r=.69, p<.001) showed higher correlation between depression and irrational faith than male students and city area students (r=.63, p<.001). Additionally, in all areas including by sex and by region, a positive correlation was shown. In all variables such as male students (r=.63, p<.001), female students (r=.72, p<.001), city area students (r=.66, p<.001), and rural area students (r=.69, p<.001), over concern and evasive faith showed the highest correlation with depression inclinations. Third, irrational faith (overall) and its sub factors such as over-self-reliance, dichotomy, determinism, over-concern and evasive faith had significant negative correlations with school adaptation (overall) and its sub factors in the scope of $r=-.27{\sim}-.52$. Determinism out of the sub factors of the irrational faith had the highest negative correlation with school adaptation (overall) and sub factors at the scope of $r=-.37{\sim}-.51$. However, over-self-reliance showed the negative correlation with school adaptation (overall) and its sub factors only partially. When looking into the results by gender, both genders showed significant negative correlation between irrational faith (overall) and its sub factors with school adaptation. Male students showed highly negative correlations with school adaptation (overall) and its sub factors in determinism ($r=-.35{\sim}-52$) and over-concern and evasive faith($r=-.31{\sim}-.51$), and fern ale students showed in over-self-reliance ($r=-.27{\sim}-.45$). However over-self-reliance showed negative correlation with school adaptation and its sub factors only partially. When looking into by region, both city and rural areas showed significant negative correlation between irrational faith (overall) and it sub factors, and school adaptation. Rural areas showed higher negative correlation in irrational faith (overall) ($r=-.39{\sim}-.53$) and over-self-reliance ($r=-.32{\sim}-.44$) and dichotomy ($r=-.28{\sim}-.39$) than city areas. However over-self-reliance showed negative correlation with school adaptation and its sub factors only partially. Fourth, depression and school adaptation showed the negative correlation in all areas. In particular, academic achievements and peer relationship showed the highest negative correlation with depression (r=-.53 p<.001). When looking into the results by sex and by region, female students (r=-.62, p<.001) and rural area students (r=-.61, p<.001) showed higher negative correlation with depression and school adaptation than female students (r=-.56, p<.001) and city area students (r=-.57, p<.001). Although there was negative correlation in all areas by sex and by region, male students (r=-.52, p<.001) and rural area students (r=-.56, p<.001) showed the highest negative correlation in peer relationship and female students (r=-.57, p<.001) and city area students (r=-.56, p<.001) showed the highest negative correlation in academic records. Based on the results of the study, it is proposed to provide elementary school students sho are likely to be depressed very easily with careful counselling and teaching based on the attention and love in school fields so that they can adapt themselves to home, school and society with positive and reasonable thinking.

• Journal of Intelligence and Information Systems
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• v.24 no.2
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• pp.59-83
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• 2018

With the increasing importance of sentiment analysis to grasp the needs of customers and the public, various types of deep learning models have been actively applied to English texts. In the sentiment analysis of English texts by deep learning, natural language sentences included in training and test datasets are usually converted into sequences of word vectors before being entered into the deep learning models. In this case, word vectors generally refer to vector representations of words obtained through splitting a sentence by space characters. There are several ways to derive word vectors, one of which is Word2Vec used for producing the 300 dimensional Google word vectors from about 100 billion words of Google News data. They have been widely used in the studies of sentiment analysis of reviews from various fields such as restaurants, movies, laptops, cameras, etc. Unlike English, morpheme plays an essential role in sentiment analysis and sentence structure analysis in Korean, which is a typical agglutinative language with developed postpositions and endings. A morpheme can be defined as the smallest meaningful unit of a language, and a word consists of one or more morphemes. For example, for a word '예쁘고', the morphemes are '예쁘(= adjective)' and '고(=connective ending)'. Reflecting the significance of Korean morphemes, it seems reasonable to adopt the morphemes as a basic unit in Korean sentiment analysis. Therefore, in this study, we use 'morpheme vector' as an input to a deep learning model rather than 'word vector' which is mainly used in English text. The morpheme vector refers to a vector representation for the morpheme and can be derived by applying an existent word vector derivation mechanism to the sentences divided into constituent morphemes. By the way, here come some questions as follows. What is the desirable range of POS(Part-Of-Speech) tags when deriving morpheme vectors for improving the classification accuracy of a deep learning model? Is it proper to apply a typical word vector model which primarily relies on the form of words to Korean with a high homonym ratio? Will the text preprocessing such as correcting spelling or spacing errors affect the classification accuracy, especially when drawing morpheme vectors from Korean product reviews with a lot of grammatical mistakes and variations? We seek to find empirical answers to these fundamental issues, which may be encountered first when applying various deep learning models to Korean texts. As a starting point, we summarized these issues as three central research questions as follows. First, which is better effective, to use morpheme vectors from grammatically correct texts of other domain than the analysis target, or to use morpheme vectors from considerably ungrammatical texts of the same domain, as the initial input of a deep learning model? Second, what is an appropriate morpheme vector derivation method for Korean regarding the range of POS tags, homonym, text preprocessing, minimum frequency? Third, can we get a satisfactory level of classification accuracy when applying deep learning to Korean sentiment analysis? As an approach to these research questions, we generate various types of morpheme vectors reflecting the research questions and then compare the classification accuracy through a non-static CNN(Convolutional Neural Network) model taking in the morpheme vectors. As for training and test datasets, Naver Shopping's 17,260 cosmetics product reviews are used. To derive morpheme vectors, we use data from the same domain as the target one and data from other domain; Naver shopping's about 2 million cosmetics product reviews and 520,000 Naver News data arguably corresponding to Google's News data. The six primary sets of morpheme vectors constructed in this study differ in terms of the following three criteria. First, they come from two types of data source; Naver news of high grammatical correctness and Naver shopping's cosmetics product reviews of low grammatical correctness. Second, they are distinguished in the degree of data preprocessing, namely, only splitting sentences or up to additional spelling and spacing corrections after sentence separation. Third, they vary concerning the form of input fed into a word vector model; whether the morphemes themselves are entered into a word vector model or with their POS tags attached. The morpheme vectors further vary depending on the consideration range of POS tags, the minimum frequency of morphemes included, and the random initialization range. All morpheme vectors are derived through CBOW(Continuous Bag-Of-Words) model with the context window 5 and the vector dimension 300. It seems that utilizing the same domain text even with a lower degree of grammatical correctness, performing spelling and spacing corrections as well as sentence splitting, and incorporating morphemes of any POS tags including incomprehensible category lead to the better classification accuracy. The POS tag attachment, which is devised for the high proportion of homonyms in Korean, and the minimum frequency standard for the morpheme to be included seem not to have any definite influence on the classification accuracy.

• Sleep Medicine and Psychophysiology
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• v.9 no.1
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• pp.24-33
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• 2002

Objectives: Nasal continuous positive airway pressure (CPAP) corrected elevated blood pressure (BP) in some studies of obstructive sleep apnea syndrome (OSAS) but not in others. Such inconsistent results in previous studies might be due to differences in factors influencing the effects of CPAP on BP. The factors referred to include BP monitoring techniques, the characteristics of subjects, and method of CPAP application. Therefore, we evaluated the effects of one night CPAP application on BP and heart rate (HR) reactivity using non-invasive beat-to-beat BP measurement in normotensive and hypertensive subjects with OSAS. Methods: Finger arterial BP and oxygen saturation monitoring with nocturnal polysomnography were performed on 10 OSAS patients (mean age $52.2{\pm}12.4\;years$; 9 males, 1 female; respiratory disturbance index (RDI)>5) for one baseline night and another CPAP night. Beat-to-beat measurement of BP and HR was done with finger arterial BP monitor ($Finapres^{(R)}$) and mean arterial oxygen saturation ($SaO_2$) was also measured at 2-second intervals for both nights. We compared the mean values of cardiovascular and respiratory variables between baseline and CPAP nights using Wilcoxon signed ranks test. Delta ($\Delta$) BP, defined as the subtracted value of CPAP night BP from baseline night BP, was correlated with age, body mass index (BMI), baseline night values of BP, BP variability, HR, HR variability, mean $SaO_2$ and respiratory disturbance index (RDI), and CPAP night values of TWT% (total wake time%) and CPAP pressure, using Spearman's correlation. Results: 1) Although increase of mean $SaO_2$ (p<.01) and decrease of RDI (p<.01) were observed on the CPAP night, there were no significant differences in other variables between two nights. 2) However, delta BP tended to increase or decease depending on BP values of the baseline night and age. Delta systolic BP and baseline systolic BP showed a significant positive correlation (p<.01), but delta diastolic BP and baseline diastolic BP did not show a significant correlation except for a positive correlation in wake stage (p<.01). Delta diastolic BP and age showed a significant negative correlation (p<.05) during all stages except for REM stage, but delta systolic BP and age did not. 3) Delta systolic and diastolic BPs did not significantly correlate with other factors, such as BMI, baseline night values of BP variability, HR, HR variability, mean SaO2 and RDI, and CPAP night values of TWT% and CPAP pressure, except for a positive correlation of delta diastolic pressure and TWT% of CPAP night (p<.01). Conclusions: We observed that systolic BP and diastolic BP tended to decrease, increase or remain still in accordance with the systolic BP level of baseline night and aging. We suggest that BP reactivity by CPAP be dealt with as a complex phenomenon rather than a simple undifferentiated BP decrease.

• Tuberculosis and Respiratory Diseases
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• v.40 no.1
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• pp.6-15
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• 1993

Background: Positive end, expiratory pressure (PEEP) has become one of the standard therapies for adult respiratory distress syndrome (ARDS). Total static compliance has been proposed as a guide to determine the size of PEEP ('best PEEP') which is of unproven clinical benefit and remains controversial. Besides increasing functional residual capacity and thus improving oxygenation, PEEP stimulate prostacyclin secretion and was proposed for the treatment of acute pulmonary embolism. But little is known about the effect of PEEP on hemodynamic and gas exchange disturbances in acute pulmonary embolism. Methods: To study the validity of total static compliance as a predictor of 'best PEEP' in ARDS and acute pulmonary embolism, experimental ARDS was induced in mongrel dog with oleic acid and acute pulmonary embolism with autologous blood clot. Then hemodynamic and gas exchange parameters were measured with serial increment of PEEP. Results:In ARDS group, total static compliance and oxygen transport were maximal at 5 cm$H_2O$, and decreased thereafter (p<0.05). With increment of PEEP, arterial oxygen tension ($PaO_2$) and arterial carbon dioxide tension ($PaCO_2$) increased and cardiac output and physiological shunt decreased. In pulmonary embolism group, total static compliance, oxygen transport, physiological shunt and cardiac output decreased and $PaO_2$ and $PaCO_2$ increased with increment of PEEP (p<0.05). Comparing the change induced by increment of PEEP by 1 cm$H_2O$ in ARDS group with that in pulmonary embolism group, there was no significant difference between two groups except cardiac output which decreased more in pulmonary embolism group (p<0.05). In ARDS group, oxygen transport and total static compliance increased after PEEP application, and total static compliance was maximal at the PEEP level where oxygen transport was maximal. However in pulmonary embolism group, oxygen transport and total static compliance decreased after application of PEEP. There was significant correlation between change of total static compliance and change of oxygen transport in both groups. Conclusion: In both ARDS and acute pulmonary embolism, it can be concluded that total static compliance is useful as a predictor of 'best PEEP'.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.31-36
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• 2013

Purpose: Measure gastric emptying time (GET: Gastric Emptying Time) is a non-invasive and quantitative evaluation methods, mainly by endoscopic or radiological examination confirmed no mechanical obstruction in patients with symptoms of congestion is checked. Such tests are not common gastric emptying time measured esophageal cancer patients (who underwent esophagectomy) patients after surgery for gastric emptying time was measured test. And the period of time for more than one year after the gastric emptying time measurement was performed. By comparing the two kinds of tests in the chest cavity after surgery as the evaluation of gastrointestinal function tests evaluate the usefulness of GET, and will evaluate the characteristics of the image. Materials and Methods: 93 patients who underwent esophagectomy with gastric emptying time measurement of subject tests immediately after surgery and after 1 year or longer were twice. Preparation of the patient before the test is more than 12 hours of overnight fasting is important, in addition to the medicine or to stop smoking, and diabetes insulin injections should be early in the morning is ideal to test. Generally labeled with $^{99m}Tc-DTPA$ resin which is used to make steamed egg, seaweed and fermented milk with a high viscosity after eating, three hours in the standing position was measured. Evaluation of gastric emptying curves on the way intragastric radioactivity level by 50% the time (half-time [T1/2]) was calculated, based on the half-life was divided into three steps: over 180 minutes was defined as delayed gastric emptying, within 180minutes was defined as intermediate gastric emptying and when all the radioisotopes were dumped into the jejunum as soon as swallowed, was defined as rapid gastric emptying. Results: Gastric emptying time of a typical images stomach of antrum and fundus additional images appear stronger over time move on to the small intestine. but esophageal cancer who underwent esophagectomy side of the thoracic cavity showed a strong image. Immediately after surgery, the half-time (T1/2) of rapid gastric emptying appeared to 12.9%, intermediate gastric emptying appeared to 52.7%, delay gastric emptying appeared to 34.4%. After more than a year the results of the half-life after surgery, 67% of rapid gastric emptying to intermediate gastric emptying was changed, 69% of delay gastric emptying to intermediate gastric emptying changed. Intermediate gastric emptying worse in patients rapid gastric emptying and the delay gastric emptying is 24% in the case. Conclusion: Esophagectomy for esophageal cancer who underwent half-time measurement test (T1/2) rapid gastric emptying and delay gastric emptying are the result of the comparison over time, changes were observed intermediate gastric emptying. Mainly seeing of gastric emptying time measurement in the esophagus instead of thoracic cavity to check the evaluation of gastrointestinal function can be useful even means. And segmentation criteria and narrow time interval of checking if more accurate information and analysis of the clinical diagnosis and evaluation seems to be done.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.534-542
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• 2012

This study was conducted to investigate the effect of 1-methylcyclopropene (1-MCP) on fruit quality and incidence of physiological disorders for keeping freshness during marketing period in Asian pear (Pyrus pyrifolia Nakai) 'Wonhwang' and 'Whasan'. Fruits were treated with $1{\mu}L{\cdot}L^{-1}$ 1-MCP for 12 hours at $25^{\circ}C$, at two or three stages of ripeness as determined by days after full bloom (DAFB). Fruits were harvested at 130 and 140 DAFB in early season cultivar 'Wonhwang' and 135, 145, and 150 DAFB in mid-season cultivar 'Whasan', respectively. Fruits were stored at $25^{\circ}C$ for 21 days and measured the flesh firmness, weight loss, soluble solids, acidity, ethylene, respiration and severity of physiological disorders at week interval. 1-MCP treatment to 'Wonhwang' pears harvested at 130 and 140 DAFB effectively delayed firmness loss during storage at $25^{\circ}C$. Untreated fruits of 'Wonhwang' pears harvested at 130 DAFB showed 32.3 and 10.1N of firmness after 14 and 21 days of shelf-life at $25^{\circ}C$, respectively, while those of the 1-MCP treated fruits showed 39.4 and 33.1N during same period. In the fruits harvested at 140 DAFB, the firmness of untreated fruit was lowered to 14.8 and 6.6N after 14 and 21 days, respectively, but those of 1-MCP treated fruit were 35.0 and 33.3N, respectively. Whereas, 1-MCP treatment delayed firmness loss only in the fruit harvested late (150 DAFB) in 'Whasan' pears. Higher soluble solids content and acidity during extended shelf-life were apparent in 1-MCP treated 'Wonhwang' pears, while those of 'Whasan' pears were little changed. 'Wonhwang' pears showed a relatively high ethylene production (maximum $0.58{\mu}l{\cdot}L^{-1}$) in the fruits harvested late than early harvested one. 'Whasan' pears showed little amount of ethylene production regardless of extended shelf-life. 1-MCP treatment to 'Wonhwang' pears decreased respiration rate following shelf-life, 42 and 50% reduction were observed at 14 days of shelf-life when compared with those of untreated ones harvested at 130 and 140 DAFB, respectively. No reduction of respiration rate by the treatment of 1-MCP was detected in 'Whasan' pears which showed considerably low respiration rate compared with 'Wonhwang' pears. Harvest time influenced the level of physiological disorders together with extension of shelf-life in both the cultivars. 1-MCP treatment completely blocked the incidence of internal browning of 'Wonhwang' pears harvested at 130 DAFB, and reduced the incidences of pithiness and core browning, while it promoted the flesh spot decay disorder regardless of harvest time. 1-MCP treatment was of little benefit for the prevention of physiological disorders in 'Whasan' pears compared with those of 'Wonhwang'.

• Childhood Kidney Diseases
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• v.3 no.1
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• pp.11-19
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• 1999

Purpose: MCNS is found in approximately $85\%$ of the idiopathic nephrotic syndrome in children and shows good prognosis with initial steroid therapy. MCNS most commonly appears between the ages of 2 and 10 yr. But the incidence and prognosis in adolescent MCNS are different from those found in young children; the prognosis and the response to therapy is unfavorable with increasing ages. So we compared the prevalence and the clinical manifestations of adolescent MCNS with that of childhood MCNS for management of adolescent MCNS. Methods: We conducted a retrospective study with a review of histopathologic findings and clinical manifestations of the 216 cases with MCNS which were divided into children group and adolescent group by their age of onset; under 12 years(childhood) and between 12-18 years(adolescent). Results: 1) The number of childhood idiopathic nephrotic syndrome was 245 cases, and that of adolescent idiopathic nephrotic syndrome was 55 cases. 188 cases($77\%$) showed MCNS, 30 cases($12\%$) FSGS, 4 cases($1.6\%$) MSPCN in childhood idiopathic nephrotic syndrome; 28 cases($51\%$) showed MCNS, 12 cases($22\%$) FSGS in adolescent idiopathic nephrotic syndrome. 2) The mean onset age was $7.53{\pm}5.5$ years, and the male to female ratio was 3.8:1 in childhood onset and 2.5:1 in adolescent onset with male predominance. 3) Hematuria was associated with $17\%$ of childhood onset and $39.3\%$ of adolescent onset disease(P=0.005). Hypertension appeared in $0.5\%\;and\;7\%$ in each group without significant difference between the groups. 4) 24 hour urine protein, SPI, albumin, BUN, cholesterol level showed no significant difference. 5) The response of childhood onset and adolescent onset MCNS to steroid therapy showed complete remission in $11.7\%\;&\;14.7\%$, infrequent relapsing in $29.2\%\;&\;28.5\%$, frequent relapsing in $23.9\%\;&\;14.7\%$, steroid dependent in $21.8\%\;&\;28.6\%$ each. Steroid resistant showed $13.3\%\;&\;14.7\%$ with no significance. 6) Immunosuppresant therapy was performed $57\%$ in childhood onset and $65\%$ in adolescent onset. 7) Mean number of relapse and duration from onset to first relapse showed no significance between two groups. Conclusion : Our results indicate that the incidence of hematuria, the rate of steroid dependent and frequent relapsing, and the recurrence rate were higher in adolescent MCNS; showed poorer steroid responsiveness and prognosis. Our data also point to the need for a more aggressive therapy to treat and make recommendations for the adolescent population as a whole.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.162-166
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• 2012

Purpose : Vitamin $B_{12}$ and Folate are for anemia work-up which is well known for its sensitivity of light; the screening manual also specifies to be careful with light conditions. According to this, our laboratory minimized the exposure of light when inspecting the Vitamin $B_{12}$ and Folate, but the exposure cannot be wholly blocked due to other various factors such as when conducting specimen segregation. Thus, this inspection is to identify to what extent light can influence and whether the exclusion of light is mandatory during the Vitamin $B_{12}$/Folate test. Materials and Methods : We have conducted two experiments of identifying the extent of light's influence when conducting the Vitamin $B_{12}$/Folate test and also when specimens are under preservation. These experiments were progressed with various concentrations of patients' specimens which were requested to our hospital in March 2012. The first experiment is to verify the results on Vitamin $B_{12}$/Folate dependent on light exposure during the experiment. In the process, we have compared the results of light exposure/exclusion during the incubation process after the reagent division. The second experiment is about the impact of light exposure on the results on Vitamin $B_{12}$/Folate during the preservation. For 1, 2, 7 days the light on the specimen were wholly blocked and were preserved under $-15^{\circ}C$ temperature refrigeration. Then, we compared the results of light-excluded specimen and the exposed one. Results : When conducting first experiment, there were no noticeable changes in the Standard and specimen's cpm, but for Vitamin $B_{12}$, the average result of specimen exposed to light increased 7.8% compare to that of excluded one's. Furthermore, in the significant level 0.05, the significance probability or the p-value was 0.251 which means it has no impact. For Folate, the result being exposed to light decreased 5.4%, the significance probability was 0.033 which means it has little impact. For the second preservation, the result was dependent on the light exposure. The first day of preservation of Vitamin $B_{12}$, the clinical material exposed to light was 11.6%, second day clinical material exposed to light was 10.8%, seventh day clinical material exposed to light increased 3.8%, the significance probability of the $1^{st}$, $2^{nd}$, $7^{th}$ day is 0.372, 0.033, 0.144 respectively, and which indicates that the $1^{st}$ and $7^{th}$ day seems to have no impact. For Folate's case, the clinical material exposed to light has increased 1.4% but hardly had impact, $2^{nd}$ day clinical material being exposed to light was 6.1%, $7^{Th}$ day clinical material being exposed to light decreased 5.2%. The significance probability of Folate on the $1^{st}$, $2^{nd}$, $7^{th}$ day is 0.378, 0.037, 0.217 respectively, and the $1^{st}$ day and the $7^{th}$ day seems to have no impact. Conclusion : After scrutinizing the impact of light exposure/exclusion, Vitamin $B_{12}$ has no impact, while Folate seems to have no noticeable influence but light exclusion is recommended due to its significance probability of 0.033 when conducting experiment. During the preservation, the $2^{nd}$ day result depend on the light exclusion seems to have impact or influence. However, to consider the complication of the experimental process, the experiment including technical errors is predictable. Hence, it is likely to have no impact of light. Nevertheless, it is recommendable to exclude the light during the long preservation as per the significance probability (p-value) of $1^{st}$ and $7^{th}$ day has been diminished.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.83-89
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• 2010

Purpose: The Wide Beam Reconstruction (WBR) algorithms that UltraSPECT, Ltd. (U.S) has provides solutions which improved image resolution by eliminating the effect of the line spread function by collimator and suppression of the noise. It controls the resolution and noise level automatically and yields unsurpassed image quality. The aim of this study is WBR of whole body bone scan in usefulness of clinical application. Materials and Methods: The standard line source and single photon emission computed tomography (SPECT) reconstructed spatial resolution measurements were performed on an INFINA (GE, Milwaukee, WI) gamma camera, equipped with low energy high resolution (LEHR) collimators. The total counts of line source measurements with 200 kcps and 300 kcps. The SPECT phantoms analyzed spatial resolution by the changing matrix size. Also a clinical evaluation study was performed with forty three patients, referred for bone scans. First group altered scan speed with 20 and 30 cm/min and dosage of 740 MBq (20 mCi) of $^{99m}Tc$-HDP administered but second group altered dosage of $^{99m}Tc$-HDP with 740 and 1,110 MBq (20 mCi and 30 mCi) in same scan speed. The acquired data was reconstructed using the typical clinical protocol in use and the WBR protocol. The patient's information was removed and a blind reading was done on each reconstruction method. For each reading, a questionnaire was completed in which the reader was asked to evaluate, on a scale of 1-5 point. Results: The result of planar WBR data improved resolution more than 10%. The Full-Width at Half-Maximum (FWHM) of WBR data improved about 16% (Standard: 8.45, WBR: 7.09). SPECT WBR data improved resolution more than about 50% and evaluate FWHM of WBR data (Standard: 3.52, WBR: 1.65). A clinical evaluation study, there was no statistically significant difference between the two method, which includes improvement of the bone to soft tissue ratio and the image resolution (first group p=0.07, second group p=0.458). Conclusion: The WBR method allows to shorten the acquisition time of bone scans while simultaneously providing improved image quality and to reduce the dosage of radiopharmaceuticals reducing radiation dose. Therefore, the WBR method can be applied to a wide range of clinical applications to provide clinical values as well as image quality.