• The Korean Journal of Nuclear Medicine
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• v.39 no.6
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• pp.421-429
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• 2005

Purpose: It has been postulated that dopamine release in the striatum underlies the reinforcing properties of nicotine. Substantial evidence in the animal studies demonstrates that nicotine interacts with dopaminergic neuron and regulates the activation of the dopaminergic system. The aim of this study was to visualize the dopamine release by smoking in human brain using PET scan with $[^{11}C]raclopride$. Materials and Methods: Five male non-smokers or ex-smokers with an abstinence period longer than 1 year (mean age of $24.4{\pm}1.7$ years) were enrolled in this study $[^{11}C]raclopride$, a dopamine D2 receptor radioligand, was administrated with bolus-plus-constant infusion. Dynamic PET was performed during 120 minutes ($3{\times}20s,\;2{\times}60s,\;2{\times}120s,\;1{\times}180s\;and\;22{\times}300s$). following the 50 minute-scanning, subjects smoked a cigarette containing 1 mg of nicotine while in the scanner. Blood samples for the measurement of plasma nicotine level were collected at 0, 5, 10, 15, 20, 25, 30, 45, 60, and 90 minute after smoking. Regions for striatal structures were drawn on the coronal summed PET images guided with co-registered MRI. Binding potential, calculated as (striatal-cerebellar)/cerebellar activity, was measured under equilibrium condition at baseline and smoking session. Results: The mean decrease in binding potential of $[^{11}C]raclopride$ between the baseline and smoking in caudate head, anterior putamen and ventral striatum was 4.7%, 4.0% and 7.8%, respectively. This indicated the striatal dopamine release by smoking. Of these, the reduction in binding potential in the ventral striatum was significantly correlated with the cumulated plasma level of the nicotine (Spearman's rho=0.9, p=0.04). Conclusion: These data demonstrate that in vivo imaging with $[^{11}C]raclopride$ PET could measure nicotine-induced dopamine release in the human brain, which has a significant positive correlation with the amount or nicotine administered bt smoking.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.3
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• pp.234-240
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• 2007

Purpose: In this study we propose a block-iterative method for reconstructing Compton scattered data. This study shows that the well-known expectation maximization (EM) approach along with its accelerated version based on the ordered subsets principle can be applied to the problem of image reconstruction for Compton camera. This study also compares several methods of constructing subsets for optimal performance of our algorithms. Materials and Methods: Three reconstruction algorithms were implemented; simple backprojection (SBP), EM, and ordered subset EM (OSEM). For OSEM, the projection data were grouped into subsets in a predefined order. Three different schemes for choosing nonoverlapping subsets were considered; scatter angle-based subsets, detector position-based subsets, and both scatter angle- and detector position-based subsets. EM and OSEM with 16 subsets were performed with 64 and 4 iterations, respectively. The performance of each algorithm was evaluated in terms of computation time and normalized mean-squared error. Results: Both EM and OSEM clearly outperformed SBP in all aspects of accuracy. The OSEM with 16 subsets and 4 iterations, which is equivalent to the standard EM with 64 iterations, was approximately 14 times faster in computation time than the standard EM. In OSEM, all of the three schemes for choosing subsets yielded similar results in computation time as well as normalized mean-squared error. Conclusion: Our results show that the OSEM algorithm, which have proven useful in emission tomography, can also be applied to the problem of image reconstruction for Compton camera. With properly chosen subset construction methods and moderate numbers of subsets, our OSEM algorithm significantly improves the computational efficiency while keeping the original quality of the standard EM reconstruction. The OSEM algorithm with scatter angle- and detector position-based subsets is most available.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.199-213
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• 2020

Grain size and shape are the two important components contributing to rice yield and quality. To analyze traits related to grain-shape, a total of 272 varieties derived from japonica, japonica black and Tongil-type rice accession in Korea were evaluated in this study. The traits, grain length (GL), grain width (GW), grain thickness (GT), length to width ratio (RLW), and 1000-grain weight (TGW) were measured and replicated 10 times. Genes (GW2, GS3, qGL3, qSW5, GS5, TGW6, GW7, and GW8) related to grain-shape were validated in the accessions using specific DNA marker sets. K-mean clustering of the accession based on phenotypic data revealed three groups: group 1 was classified by GW and GT and included most of japonica type, group 2 was classified by RLW and GL reached a medium size and possessed a half spindle-shaped type, and group 3 was classified by TGW, reached a long size and possessed a semi-round shape. In validation tests using the marker sets, both gw2 and tgw6 were validated in less than 1% of the tested accessions and two allelic types, qgl3 and gw8, were only verified in Tongil-type accessions. For GW8 and GW2, any different amplicons were not amplified in any japonica or Tongil-type accessions, respectively. In order to suggest the representative grain-shape gene combinations for each ecotype, the allelic combinations were evaluated by PCR analysis. Cj1 and 2 in japonica (Cj1-7), Cj_b1 and 2 in japonica-black (Cj_b1-3), and CT3 in Tongil-type (CT1-13) turned out to be the dominant combination in each ecotype, respectively. In addition, the results revealed that introgression of four genes (gw2, gs3, qSW5, and GS5) would expand the diversity of grain shape in Korean japonica varieties. The gene combinations information could be utilized practically to understand or enhance grain shape in japonica rice breeding program.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.2
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• pp.87-92
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• 2015

Purpose When the patients takes myocardial perfusion SPECT using $^{201}Tl$, the operator gives the patients an injection of $^{201}Tl$. But the uniformity correction map in SPECT uses $^{99m}Tc$ uniformity correction map. Thus, we want to compare the image quality when it uses $^{99m}Tc$ uniformity correction map and when it uses $^{201}Tl$ uniformity correction map. Materials and Methods Phantom study is performed. We take the data by Asan medical center daily QC condition with flood phantom including $^{201}Tl$ 21.3 kBq/mL. After postprocessing with this data, we analyze CFOV integral uniformity(I.U) and differential uniformity(D.U). And we take the data with Jaszczak ECT Phantom by American college of radiology accreditation program instruction including $^{201}Tl$ 33.4 kBq/mL. After post processing with this data, we analyze spatial Resolution, Integral Uniformity(I.U), coefficient of variation(C.V) and Contrast with Interactive data language program. Results In the flood phantom test, when it uses $^{99m}Tc$ uniformity correction map, Flood I.U is 3.6% and D.U is 3.0%. When it uses $^{201}Tl$ uniformity correction map, Flood I.U is 3.8% and D.U is 2.1%. The flood I.U is worsen about 5%, but the D.U is improved about 30% inversely. In the Jaszczak ECT phantom test, when it uses $^{99m}Tc$ uniformity correction map, SPECT I.U, C.V and contrast is 13.99%, 4.89% and 0.69. When it uses $^{201}Tl$ uniformity correction map, SPECT I.U, C.V and contrast is 11.37%, 4.79% and 0.78. All of data are improved about 18%, 2%, 13% The spatial resolution was no significant changes. Conclusion In the flood phantom test, Flood I.U is worsen but Flood D.U is improved. Therefore, it's uncertain that an image quality is improved with flood phantom test. On the other hand, SPECT I.U, C.V, Contrast are improved about 18%, 2%, 13% in the Jaszczak ECT phantom test. This study has limitations that we can't take all variables into account and study with two phantoms. We need think about things that it has a good effect when doctors decipher the nuclear medicine image and it's possible to improve the image quality using the uniformity correction map of other radionuclides other than $^{99m}Tc$, $^{201}Tl$ when we make other nuclear medicine examinations.

• The Korean Journal of Nuclear Medicine Technology
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• v.22 no.1
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• pp.55-66
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• 2018

Purpose In PET/CT exam, washed-out artifact could occur due to severe motion of the patient and high specific activity, it results in lowering not only qualitative reading but also quantitative analysis. Scatter limitation correction by GE is an algorism to correct washed-out artifact and recover the images in PET scan. The purpose of this study is to measure the threshold of specific activity which can recovers to original uptake values on the image shown with washed-out artifact from phantom experiment and to compare the quantitative analysis of the clinical patient's data before and after correction. Materials and Methods PET and CT images were acquired in having no misalignment(D0) and in 1, 2, 3, 4 cm distance of misalignment(D1, D2, D3, D4) respectively, with 20 steps of each specific activity from 20 to 20,000 kBq/ml on $^{68}Ge$ cylinder phantom. Also, we measured the distance of misalignment of foley catheter line between CT and PET images, the specific activity which makes washed-out artifact, $SUV_{mean}$ of muscle in artifact slice and $SUV_{max}$ of lesion in artifact slice and $SUV_{max}$ of the other lesion out of artifact slice before and after correction respectively from 34 patients who underwent $^{18}F-FDG$ Fusion Whole Body PET/CT exam. SPSS 21 was used to analyze the difference in the SUV between before and after scatter limitation correction by paired t-test. Results In phantom experiment, $SUV_{mean}$ of $^{68}Ge$ cylinder decreased as specific activity of $^{18}F$ increased. $SUV_{mean}$ more and more decreased as the distance of misalignment between CT and PET more increased. On the other hand, the effect of correction increased as the distance more increased. From phantom experiments, there was no washed-out artifact below 50 kBq/ml and $SUV_{mean}$ was same from origin. On D0 and D1, $SUV_{mean}$ recovered to origin(0.95) below 120 kBq/ml when applying scatter limitation correction. On D2 and D3, $SUV_{mean}$ recovered to origin below 100 kBq/ml. On D4, $SUV_{mean}$ recovered to origin below 80 kBq/ml. From 34 clinical patient's data, the average distance of misalignment was 2.02 cm and the average specific activity which makes washed-out artifact was 490.15 kBq/ml. The average $SUV_{mean}$ of muscles and the average $SUV_{max}$ of lesions in artifact slice before and after the correction show a significant difference according to a paired t-test respectively(t=-13.805, p=0.000)(t=-2.851, p=0.012), but the average $SUV_{max}$ of lesions out of artifact slice show a no significant difference (t=-1.173, p=0.250). Conclusion Scatter limitation correction algorism by GE PET/CT scanner helps to correct washed-out artifact from motion of a patient or high specific activity and to recover the PET images. When we read the image occurred with washed-out artifact by measuring the distance of misalignment between CT and PET image, specific activity after applying scatter limitation algorism, we can analyze the images more accurately without repeating scan.

• Childhood Kidney Diseases
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• v.5 no.1
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• pp.51-58
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• 2001

Purpose : Treatment of primary nocturnal enuresis (PNE) includs folk remedies and various treatments based on pathogenesis. We assessed the therapeutic effect of nocturnal water restrict ion as the primary treatment of PNE. Materials and methods : From October 1998 to June 1999, 41 children with PNE (>3 wet nights per week) who visited Ewha Womans University Mokdong hospital and who had good compliances to nocturnal water restriction for 2 months were included. Before and during nocturnal water restriction, daily fluid intake and urine volume were recorded for 2 days every 2 weeks. Responses to nocturnal water restriction were classified according to the decrease of wet nights as complete (>90$\%$), partial (50-90$\%$) and no (<50$\%$) response. Predictors such as age, sex, daytime voiding dysfunction, fluid intake, urine volume, maximum urine volume per void and fasting urine osmolality were evaluated. Results . The response rate to nocturnal water restriction fir 2 month was 82.9$\%$(34/41) [complete response 39.0$\%$(16/41), partial response : 43.9$\%$(18/41)]. The response rate to nocturnal water restriction was significantly higher in monosymptomatic PNE than polysymptomatic PNE and more effective in PNE with or nocturnal fluid intake, nocturnal urine volume, and maximum urine volume than lower nocturnal fluid intake, nocturnal urine volume and maximum urine volume per void (P<0.05). Nocturnal urine volume, maximum urine volume per void and luting urine osmolality after nocturnal water restriction has significantly increased higher in complete response and partial response group than in no response group (P<0.05). Conclusion : The nocturnal water restriction was effective in monosymptomatic PNE with nocturnal polydypsia, nocturnal polyuria and high bladder capacity. (J, Korean Soc Pediatr Nephrol 5 : 51- 8, 2001)

• Pediatric Infection and Vaccine
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• v.12 no.2
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• pp.166-177
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• 2005

Purpose : The purpose of this study was to examine the molecular epidemiology and genetic variability of adenovirus(Ad) serotypes Ad1, Ad2, and Ad5 over 14 years in Korea. Methods : A total of 382 adenoviral strains isolated from the nasopharyngeal aspirates of children with lower respiratory tract infections in Seoul, Korea from November 1990 to February 2003 were serotyped by neutralization assay with type-specific antisera. Viral DNAs were extracted from infected cell lysates by the modified Hirt procedure. Genome type(GT) was determined by DNA restriction analysis with 12 restriction enzymess(BamHI, BclI, BglI, BglII, BstEII, EcoRI, HindIII, HpaI, SalI, SmaI, XbaI, and XhoI). To evaluate the genetic relatedness, pairwise comigrating restriction fragments(PCRF) analysis was performed. Results : Of 382 strains, 33 strains(9%) were Ad1, 45 strains(12%) were Ad2, and 24 strains(6%) were Ad5. Eighteen GTs(Ad1p1-Ad1p7, Ad1a, Ad1b, Ad1b1-Ad1b3, Ad1c, Ad1d, Ad1e, Ad1e1, Ad1e2, Ad1f) among Ad1, 24(Ad2p1-Ad2p11, Ad2a, Ad2a1-Ad2a6, Ad2b, Ad2c, Ad2d, Ad2e, Ad2e1-Ad2e3) among Ad2, and 10(Ad5p1, Ad5p2, Ad5a, Ad5a1-Ad5a7) among Ad5 strains were identified. One or two strains of the vast majority of GTs were isolated during the study period while a few GTs were identified sporadically with more than 2 strains. It is notable that some GTs such as Ad1p5 and Ad5a1 appeared in cluster during a short period. In analysis of genetic relatedness, the degree of PCRFs(pairwise comigrating restriction fragments) for Ad1 varied from 79 to 99%, for Ad2, 82 to 99%, and for Ad5, 85 to 99%. Conclusion : This study established the comprehensive nomenclature systems of Ad1, Ad2, and Ad5. Diverse GTs identified in this study have crucial implications in the genomic diversity and epidemiological characteristics of Ad1, Ad2, and Ad5.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.4
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• pp.245-256
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• 1978

The effects of different particle size distribution of fused phosphate on the changes of phosphorus content in soil and plant, growth and yield of paddy rice were investigated through pot and field experiments. The following results were obtained. 1. Negative correlation was found between unhulled rice yield and the composition of fused phosphate whose particle size was larger than 28 mesh, and 65 to 150 mesh, and highly significant correlation was found between unhulled rice yield and the composition of fused phosphate whose particle size was 28 to 48 mesh. But no significant correlation was found betweeen unhulled rice yield and the composition of fused phosphate whose particle size was 48 to 65 mesh. Thus the composition of 56% of 28 to 48 mesh particles and 44% of 48 to 65 mesh particles would give the best effect. 2. In the soil of the Jeonbug series rice plant in the plots treated with fine single textured fused phosphate showed poor early growth, i.e. poor tillering and short plant height. But at harvesting stage it showed rather increased number of tillers and higher plant height. Of the composite fused phosphate the more particles of 28 to 48 mesh it had, the better growth it showed. In the soil of the Yesan series rice plant in the treated plots showed much better tillering and higher plant height in contrast with that in the control plots. Of the single textured fused phosphate the finer particles showed better growth, while of the composite fused phosphate the more particles finer than 48 mesh it had, the poorer the tillering. 3. The content of available phosphorus in the soil tended to increase as the particles of both single textured and composite phosphate became finer. The soil phosphorus content decreased as the content of phosphorus absorbed by rice plant increased at each stage of growth, and the amount of soil phophorus decreased became larger as the the particles were finer. The amount of available phosphorus in the treated soils was larger in the soil of the Yesan series than in the soil of the Jeonbug series which was a long cultivated soil and contained relatively high phosphorus. 4. In the single textured fused phosphate the amount of phosphorus absorbed by rice plant tended to increase as the particles were finer, and great difference was found at heading stage, but at harvesting stage little difference was found for all the plots. In the field experiment in the soil of the Jeonbug series more phosphorus was absorbed by rice plant in the plots treated with the composite fused phosphate of higher content of 28 to 48 mesh particles. In the pot experiment the amount of phosphorus absorbed by rice plant was highest in the plots treated with the composite fused phosphate of 53.35% of particles larger than 48 mesh and 46.6% of particles smaller than 48 mesh. In the pot experiment in the Yesan series the amount of absorbed phophorus was highest in the plots treated with the fused phosphate of 47.75% of particles larger than 48 mesh and 50. 216% of particles smaller than 48 mesh. 5. A reverse relationship was found between the absorbed phosphorus and silica. In the pot experiment in the soils of both the Jeonbug and Yesan series the amount of phosphorus absorbed by rice plant increased as the particles were finer, while the amount of absorbed silica tended to decrease.

• Radiation Oncology Journal
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• v.24 no.4
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• pp.230-236
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• 2006

$\underline{Purpose}$: To analyze the response, toxicity, patterns of failure and survival rate of patients with locally advanced non-small cell lung cancer who were treated with concurrent chemoradiotherapy with weekly paclitaxel. $\underline{Materials\;and\;Methods}$: Twenty-three patients with locally advanced non-small cell lung cancer patients who received radical chemoradiotherapy from October 1999 to September 2004 were included in this retrospective study. Patients received total $55.4{\sim}64.8$ (median 64.8) Gy (daily 1.8 Gy per fraction, 5 days per weeks) over $7{\sim}8$ weeks. 50 or $60\;mg/m^2$ of paclitaxel was administered on day 1, 8, 15, 22, 29 and 36 of radiotherapy. Four weeks after the concurrent chemoradiotherapy, three cycles of consolidation chemotherapy consisted of paclitaxel $135\;mg/m^2$ and cisplatin $75\;mg/m^2$ was administered every 3 weeks. $\underline{Results}$: Of the 23 patients, 3 patients refused to receive the treatment during the concurrent chemoradiotherapy. One patient died of bacterial pneumonia during the concurrent chemoradiotherapy. Grade 2 radiation esophagitis was observed in 4 patients (17%). Sixteen patients received consolidation chemotherapy. During the consolidation chemotherapy, 8 patients (50%) experienced grade 3 or 4 neutropenia and one of those patients died of neutropenic sepsis. Overall response rate for 20 evaluable patients was 90% including 4 complete responses (20%) and 14 partial responses (70%). Among 18 responders, 9 had local failure, 3 had local and distant failure and 2 had distant failure only. Median progression-free survival time was 9.5 months and 2-year progression-free survival rate was 19%. Eleven patients received second-line or third-line chemotherapy after the treatment failure. The median overall survival time was 21 months. 2-year and 5-year survival rate were 43% and 33%, respectively. Age, performance status, tumor size were significant prognostic factors for progression-free survival. $\underline{Conclusion}$: Concurrent chemoradiotherapy with weekly paclitaxel revealed high response rate and low toxicity rate. But local failure occurred frequently after the remission and large tumor size was a poor prognostic factor. Further investigations are needed to improve the local control.

• Radiation Oncology Journal
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• v.28 no.1
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• pp.1-8
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• 2010

Purpose: This retrospective study was performed to evaluate the efficacy of radiation therapy (RT) and to investigate the prognostic factors for thymoma when treated with RT. Materials and Methods: We analyzed 21 patients with thymoma and also received RT from March 2002 to January 2008. The median follow-up time was 37 months (range, 3 to 89 months). The median patient age was 57 years (range, 24 to 77 years) and the gender ratio of males to females was 4：3. Of the 21 patients, complete resections (trans-sternal thymectomy) and R2 resections were performed in 14 and 1 patient, respectively. A biopsy was performed in 6 patients (28.7%). The WHO cell types in the 21 patients were as follows: 1 patient (4.8%) had type A, 10 patients (47.6%) had type B1-3, and 10 patients (47.6%) had type C. Based on Masaoka staging, 10 patients (47.6%) were stage II, 7 patients (33.3%) were stage III, and 4 patients (19.1%) were stage IVa. Three-dimensional RT was adminstered to the tumor volume (planned target volume), including the anterior mediastinum and the residual disease. The total RT dose ranged from 52.0 to 70.2 Gy (median dose, 54 Gy). Consistent with the WHO criteria, the response rate was only analyzed for the 6 patients who received a biopsy only. The prognostic factors analyzed for an estimate of survival included age, gender, tumor size, tumor pathology, Masaoka stage, the possibility of treatment by performing surgery, the presence of myasthenia gravis, and RT dose. Results: The 3-year overall survival rate (OS) and the progression free survival rate (PFS) were 80.7% and 78.2%, respectively. Among the 10 patients with WHO cell type C, 3 of 4 patients (75%) who underwent a complete resection and 3 of 6 patients (50%) who underwent a biopsy survived. Distant metastasis developed in 4 patients (19.1%). The overall response rate in the 6 patients who received biopsy only were as follows: partial remission in 4 patients (66.7%), stable disease in 1 patient (16.6%), and progressive disease in 1 patient (16.6%). Acute RTOG radiation pneumonitis occurred in 1 patient (4.8%), grade 2 occurred in 2 patients (9.5%), grade 3 occurred in 1 patient (4.8%), and grade 4 occurred in 1 patient (4.8%). A univariate analysis revealed that the significant prognostic factors for OS were age (${\geq}60$, 58.3%; <60, 100%; p=0.0194), pathology (WHO cell type A-B3, 100%; C, 58.3%; p=0.0194) and, whether the patient underwent surgery (yes, 93.3%; no, 50%; p=0.0096). Conclusion: For the 15 patients who received surgery, there was no local failure within the radiation field. In patients with WHO cell type C, surgical procedures could have resulted in a more favorable outcome than biopsy alone. We report here our clinical experience in 21 patients with thymoma who were treated by radiation therapy.