• Title/Summary/Keyword: Radiation quality

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Comparison of total body irradiation-based or non-total body irradiation-based conditioning regimens for allogeneic stem cell transplantation in pediatric leukemia patients (소아 백혈병 환자의 동종 조혈모세포이식 전처치로서 전신방사선 조사 포함군과 비포함군의 비교)

  • Kim, Sang-Jeong;Han, Dong-Kyun;Baek, Hee-Jo;Kim, Dong-Yeon;Nam, Taek-Keun;Hwang, Tai-Ju;Kook, Hoon
    • Clinical and Experimental Pediatrics
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    • v.53 no.4
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    • pp.538-547
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    • 2010
  • Purpose : This study aims to compare the outcome of total body irradiation (TBI)- or non-TBI-containing conditioning regimens for leukemia in children. Methods : We retrospectively evaluated 77 children conditioned with TBI (n=40) or non-TBI (n=37) regimens, transplanted at Chonnam National University Hospital between January 1996 and December 2007. The type of transplantation, disease status at the time of transplant, conditioning regimen, engraftment kinetics, development of graft-versus-host disease (GVHD), complications, cause of deaths, overall survival (OS), and event-free survival (EFS) were compared between the 2 groups. Results : Among 34 patients with acute lymphoblastic leukemia (ALL), 28 (82.4%) were in the TBI group, while 72.7% (24/33) of patients with myeloid leukemia were in the non-TBI group. Although the 5-year EFS of the 2 groups was similar for all patients (62% vs 63%), the TBI group showed a better 5-year EFS than the non-TBI group when only ALL patients were analyzed (65% vs 17%; $P$=0.005). In acute myelogenous leukemia patients, the non-TBI group had better survival tendency (73% vs 38%; $P$=0.089). The incidence of GVHD, engraftment, survival, cause of death, and late complications was not different between the 2 groups. Conclusion : The TBI and non-TBI groups showed comparable results, but the TBI group showed a significantly higher 5-year EFS than the non-TBI group in ALL patients. Further prospective, randomized controlled studies involving larger number of patients are needed to assess the late-onset complications and to compare the socioeconomic quality of life.

A Computer Simulation for Small Animal Iodine-125 SPECT Development (소동물 Iodine-125 SPECT 개발을 위한 컴퓨터 시뮬레이션)

  • Jung, Jin-Ho;Choi, Yong;Chung, Yong-Hyun;Song, Tae-Yong;Jeong, Myung-Hwan;Hong, Key-Jo;Min, Byung-Jun;Choe, Yearn-Seong;Lee, Kyung-Han;Kim, Byung-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.38 no.1
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    • pp.74-84
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    • 2004
  • Purpose: Since I-125 emits low energy (27-35 keV) radiation, thinner crystal and collimator could be employed and, hence, it is favorable to obtain high quality images. The purpose of this study was to derive the optimized parameters of I-125 SPECT using a new simulation tool, GATE (Geant4 Application for Tomographic Emission). Materials and Methods: To validate the simulation method, gamma camera developed by Weisenberger et al. was modeled. Nal(T1) plate crystal was used and its thickness was determined by calculating detection efficiency. Spatial resolution and sensitivity curves were estimated by changing variable parameters for parallel-hole and pinhole collimator. Peformances of I-125 SPECT equipped with the optimal collimator were also estimated. Results: in the validation study, simulations were found to agree well with experimental measurements in spatial resolution (4%) and sensitivity (3%). In order to acquire 98% gamma ray detection efficiency, Nal(T1) thickness was determined to be 1 mm. Hole diameter (mm), length (mm) and shape were chosen to be 0.2:5:square and 0.5:10:hexagonal for high resolution (HR) and general purpose (GP) parallel-hole collimator, respectively. Hole diameter, channel height and acceptance angle of pinhole (PH) collimator were determined to be 0.25 mm, 0.1 mm and 90 degree. The spatial resolutions of reconstructed image of the I-125 SPECT employing HR:GP:PH were 1.2:1.7:0.8 mm. The sensitivities of HR:GP:PH were 39.7:71.9:5.5 cps/MBq. Conclusion: The optimal crystal and collimator parameters for I-125 Imaging were derived by simulation using GATE. The results indicate that excellent resolution and sensitivity imaging is feasible using I-125 SPECT.

Evaluation of Dosimetric Characteristics of Small Field in Cone Versus Square Fields Based on Linear Accelerators(LINAC) for Stereotactic Radiosugery(SRS) (선형가속기를 기반으로 한 뇌정위 방사선 수술 시 전용 콘과 정방형 소조사면의 선량 특성에 관한 고찰)

  • Yoon, Joon;Lee, Gui-Won;Park, Byung-Moon
    • Journal of radiological science and technology
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    • v.33 no.1
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    • pp.61-66
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    • 2010
  • In this paper we evaluated small field dose characteristics of exclusive cone fields versus square fields for stereotactic radiosugery (SRS) which is based on linear accelerators (LINAC). For this test, we used a small beam detector (stereotactic fields detector : SFD) with a 6 MV photon beam and a water phantom system (IBA, Germany). Percentage depth dose (PDD) was measured for different field sets (cones : ${\Phi}1\;cm$, ${\Phi}2\;cm$, ${\Phi}3\;cm$ ; square fields : $1{\times}1\;cm^2$, $2{\times}2\;cm^2$, $3{\times}3\;cm^2$) at a source skin distance (SSD) of 100 cm. We measured the point depths at 1.5 cm, 5 cm, 10 cm, 20 cm, and 30 cm. The output factors were measured under the same geometrical conditions of the PDD and normalized at the maximum dose depth. To analyze the penumbra, we measured the dose profile with 95 cm of SSD, 5 cm of depth for each field sizes (${\Phi}1\;cm$, ${\Phi}3\;cm$, $1{\times}1\;cm^2$, and $3{\times}3\;cm^2$) using SFD. We obtained the values for every 1 mm interval in the physical field (90%) and 0.5 mm interval in the penumbra region (20 to 80%). The PDD variation of exclusive cones and square fields were 4.3 to 7.9% lesser than the standard field size ($10{\times}10\;cm^2$. The variation of PDD was reduced while the field size was increased. To compare the beam quality, we analyzed the $PDD_{20,10}$ and the results showed under the 1% of variations for all experiments except for ${\Phi}1\;cm$ cone and $1{\times}1\;cm^2$ fields. Output factors of exclusive cone were increased 3.1~4.6% than the square fields, and the penumbra region of exclusive cone was reduced 20% as compared to the square fields. As the previous researches report, it is very important for SRS and SFD that precise dosimetry in small beam fields. In this paper, we showed the effectiveness of exclusive cone, compared to square field. And we will study on the various detector characteristics for small beam fields.

Optimization of Subtraction Brain Perfusion SPECT with Basal/Acetazolamide Consecutive Acquisition (기저/아세타졸아미드 부하 연속 촬영 뇌관류 SPECT 최적화)

  • Lee, Dong-Soo;Lee, Tae-Hoon;Kim, Kyeong-Min;Chung, June-Key;Lee, Myung-Chul;Koh, Chang-Soon
    • The Korean Journal of Nuclear Medicine
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    • v.31 no.3
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    • pp.330-338
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    • 1997
  • This study investigated the method to adjust acquisition time(a) and injection dose (i) to make the best basal and subtraction images in consecutive SPECT. Image quality was assumed to be mainly affected by signal to noise ratio(S/N). Basal image was subtracted from the second image consecutively acquired at the same position. We calculated S/N ratio in basal SPECT images($S_1/N_1$) and subtraction SPECT images(Ss/Ns) to find a(time) and i(dose) to maximize S/N of both images at the same time. From phantom images, we drew the relation of image counts and a(time) and i(dose) in our system using fanbeam-high-resolution collimated triple head SPECT. Noise by imaging process depended on Poisson distribution. We took maximum tolerable duration of consecutive acquisition as 30 minutes and maximum injectible dose as 1,850MBq(50 mCi)(sum of two injections) per study. Counts of second-acquired image($S_2$), counts($S_s$) and noise($N_s$) of subtraction SPECT were as follows. $C_1$ was the coefficient of measurement with our system. $$S_2=S_1{\cdot}(\frac{30-a}{a})+background{\cdot}(1-\frac{30-a}{a})+C_1{\cdot}(30-a){\cdot}{\epsilon}{\cdot}(50-i)$$ $$Ss=S_2-\{S_1{\cdot}(\frac{30-a}{a})+background{\cdot}(1-\frac{(30-a)}{a})\}$$ $$Ns={\sqrt{N_2^2+N_1^2{\cdot}\frac{(30-a)^2}{a^2}}={\sqrt{S_2+S_1{\cdot}\frac{(30-a)^2}{a^2}}$$ In case of rest/acetazolamide study, effect(${\epsilon}$) of acetazolamide to increase global brain uptake of Tc-99m-HMPAO could be 1.5 or less. Varying ${\epsilon}$ from 1 to 1.5, a(time) and i(dose) pair to maximize both $S_1/N_l$ and Ss/Ns was determined. 15 mCi/17 min and 35mCi/13min was the best a(time) and i(dose) pair for rest/acetazolamide study(when ${\epsilon}$ were 1.2) and came to be used for our clinical routine after this study. We developed simple method to maximize S/N ratios of basal and subtraction SPECT from consecutive acquisition. This method could be applied to ECD/HMPAO and brain activation studies as well as rest/acetazolamide studies.

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Needs and Satisfaction of Cancer Patients on the Medical Services in Jeju Special Self-Governing Province (제주지역 암환자의 의료서비스 요구도 및 만족도 분석)

  • Kim, Woo-Jeong;Kim, Min-Young;Chang, Weon-Young;Choi, Jae-Hyuck
    • Journal of Hospice and Palliative Care
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    • v.13 no.3
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    • pp.153-160
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    • 2010
  • Purpose: The purpose of the present study was to investigate needs and satisfaction on the medical services of cancer patients in Jeju Special Self-Governing Province. Methods: Total 174 cancer patients, who visited at the clinic of Jeju National University Hospital, submitted informed consent and participated in this study from July 13 to July 30, 2009. Self questionnaire was used and data were analyzed with Kolmogorov-Smirnov test, Mann-Whitney U test, ANOVA, and Kruskal-Wallis test. Results: Participants expressed the needs of most economical support (3.38 out of 4), followed by counseling of treatment plan (3.22), information of disease (3.07), and disease management except cancer (2.97). Participants were satisfied most with religious counseling (3.41), followed by nursing service support (3.39), employment counseling (3.26), and counseling for family or interpersonal relationships (3.26). The satisfaction of economical support was the lowest (1.98). Satisfaction of men was higher than women, and needs in patients who were living with children was the highest. Patients who were living alone or with children showed the lowest satisfaction about the medical services. There were no significant differences in the general characteristics, however, participants who were older than 60 years of age or had higher income showed lower needs and higher satisfaction. There were no significant differences in the medical characteristics, however, thyroid cancer patients and patients who were treated with radiation therapy or transarterial embolization showed low satisfaction. Conclusion: Cancer patients seemed to need more economical support, information of treatment or disease, and symptom management. Furthermore, there were various needs about the services, depending on family formation or economical support of patients. Therefore, it is certain that patients who were suffering from other cancers, except the 5 major cancers, needed more services. In conclusion, continuous and systemic policy to consider patient's characteristics and needs are needed in community as well as health care system.

Parameter Sensitivity Analysis for Spatial and Temporal Temperature Simulation in the Hapcheon Dam Reservoir (합천댐 저수지에서의 시공간적 수온모의를 위한 매개변수 민감도 분석)

  • Kim, Boram;Kang, Boosik
    • Journal of Korea Water Resources Association
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    • v.46 no.12
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    • pp.1181-1191
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    • 2013
  • This study have implemented finding the optimal water temperature parameter set for Hapcheon dam reservoir using CE-QUAL-W2 model. In particular the sensitivity analysis was carried out for four water temperature parameters of wind sheltering coefficient (WSC), radiation heat coefficient (BETA), light extinction coefficient (EXH2O), heat exchange coefficient at the channel bed (CBHE). Firstly, WSC, BETA, EXH2O shows relatively high sensitivity in common during April to September, and CBHE does during August to November. Secondly, as a result of identifying depth range of parameter influence, BETA and EXH2O show 0~9 m and 8~14 m which is thermocline layer close to water surface, CBHE is deep layer 12 m away from bottom. Finally, applying annual or monthly optimal parameter sets indicates that the bias between two sets does not show much differences for WSC and CBHE parameters, but BETA and EXH2O parameters show $0.20^{\circ}C$ and $0.51^{\circ}C$ of monthly average biases for two parameter sets. In particular the bias reveals to be $0.4^{\circ}C$ and $1.09^{\circ}C$ during May and August that confirms the necessity of use of monthly parameters during that season. It is claimed that the current operational custom use of annual parameters in calibration of reservoir water quality model requires the improvement of using monthly parameters.

Comparing Photosynthesis, Growth, and Yield of Paprika (Capsicum annuum L. 'Cupra') under Supplemental Sulfur Plasma and High-Pressure Sodium Lamps in Growth Chambers and Greenhouses (황 플라즈마 및 고압나트륨 램프의 보광에 따른 생육상 및 온실에서의 파프리카 광합성 및 생산성 비교)

  • Park, Kyoung Sub;Kwon, Dae Young;Lee, Joon Woo;Son, Jung Eek
    • Journal of Bio-Environment Control
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    • v.27 no.4
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    • pp.332-340
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    • 2018
  • Supplemental lighting with artificial light sources is a practical method that enables normal growth and enhances the yield and quality of fruit vegetable in greenhouses. The objective of this study was to investigate the effect of sulfur plasma lamp (SP) and high-pressure sodium lamp (HPS) as supplemental lighting sources on the growth and yield of paprika. For investigating the effectiveness of SP and HPS lamps on paprika, the effects of primary lighting on plant growth were compared in growth chambers and those of supplemental lighting were also compared in greenhouses. In the growth chamber, plant height, leaf area, stem diameter, number of leaves, fresh weight, and dry weight were measured weekly at SP and HPS from 2 weeks after transplanting. In the greenhouse, no supplemental lighting (only sunlight) was considered as the control. The supplemental lights were turned on when outside radiation became below $100W{\cdot}m^{-2}$ from 07:00 to 21:00. From 3 weeks after supplemental lighting, the growth was measured weekly, while the number and weight of paprika fruits measured every two weeks. In the growth chamber, the growth of paprika at SP was better than at HPS due to the higher photosynthetic rate. In the greenhouse, the yield was higher under sunlight with either HPS or SP than sunlight only (control). No significant differences were observed in plant height, number of node, leaf length, and fresh and dry weights between SP and HPS. However, at harvest, the number of fruits rather than the weight of fruits were higher at SP due to the enhancement of fruiting numbers and photosynthesis. SP showed a light spectrum similar to sunlight, but higher PAR and photon flux sum of red and far-red wavelengths than HPS, which increased the photosynthesis and yield of paprika.

Development of Marker-free Transgenic Rice Expressing the Wheat Storage Protein, Glu-1Dy10, for Increasing Quality Processing of Bread and Noodles (빵과 면의 가공적성 증진을 위한 밀 저장단백질 Glu-1Dy10을 발현하는 마커프리 형질전환 벼 개발)

  • Park, Soo-Kwon;Shin, DongJin;Hwang, Woon-Ha;Hur, Yeon-Jae;Kim, Tae-Heon;Oh, Se-Yun;Cho, Jun-Hyun;Han, Sang-Ik;Lee, Seung-Sik;Nam, Min-Hee;Park, Dong-Soo
    • Journal of Life Science
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    • v.24 no.6
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    • pp.618-625
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    • 2014
  • Rice flour is used in many food products. However, dough made from rice lacks extensibility and elasticity, making it less suitable than wheat for many food products such as bread and noodles. The high-molecular weight glutenin subunits (HMW-GS) of wheat play a crucial role in determining the processing properties of the wheat grain. This paper describes the development of marker-free transgenic rice plants expressing a wheat Glu-Dy10 gene encoding the HMG-GS from the Korean wheat cultivar 'Jokyeong' using Agrobacterium-mediated co-transformation. Two expression cassettes, consisting of separate DNA fragments containing Glu-1Dy10 and hygromycin phosphotransferase II (HPTII) resistance genes, were introduced separately into Agrobacterium tumefaciens EHA105 for co-infection. Each EHA105 strain harboring Glu-1Dy10 or HPTII was infected into rice calli at a 3: 1 ratio of Glu-1Bx7 and HPTII. Among 290 hygromycin-resistant $T_0$ plants, we obtained 29 transgenic lines with both the Glu-1Dy10 and HPTII genes inserted into the rice genome. We reconfirmed the integration of the Glu-1Dy10 gene into the rice genome by Southern blot analysis. Transcripts and proteins of the Glu-1Dy10 in transgenic rice seeds were examined by semi-quantitative RT-PCR and Western blot analysis. The marker-free plants containing only the Glu-1Dy10 gene were successfully screened in the $T_1$ generation.

Studies on Microbiological and Chemical Characteristics of Gamma-Irradiated Soybean Powder (감마선 조사된 대두분의 미생물학적 및 이화학적 특성 연구)

  • Kim, Hee-Yun;Song, Kyong-Hee;Hong, Jin-Hwan;Kim, Dong-Sul;Han, Sang-Bae;Lee, Eun-Ju;Kang, Kil-Jin;Chung, Hyung-Wook;Im, Moo-Hyeog;Kim, Chang-Min;Kwon, Yong-Kwan;Chin, Myung-Shik;Song, In-Hwan;Byun, Myung-Woo;Bae, Dong-Ho;Shin, Il-Shik;Ha, Sang-Chul
    • Korean Journal of Food Science and Technology
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    • v.34 no.6
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    • pp.962-968
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    • 2002
  • Effects of gamma-irradiation of 1 to 10 kGy on the microbial growth, contents of amino acids, fatty acids, and free sugars, and changes in acid values in soybean powder were studied. Irradiation doses at $3{\sim}5\;kGy$ inhibited the mold growth completely in two kinds of imported soybean powders. Contents of sulfur-containing amino acids, such as cysteine, in both soybean powders decreased with irradiation, whereas no significant changes in free amino acid and fatty acid contents of both soybean powders were observed. Free sugar contents of stachyose and sucrose in Chinese soybean powder decreased with increasing irradiation dose level, whereas, those of other sugars remained unchanged. Results of this study confirm that $3{\sim}5\;kGy$ irradiation can be safely applied to apply to soybean powder without causing significant quality deteriorations microbiologically and chemically.

Estimation of Reference Crop Evapotranspiration Using Backpropagation Neural Network Model (역전파 신경망 모델을 이용한 기준 작물 증발산량 산정)

  • Kim, Minyoung;Choi, Yonghun;O'Shaughnessy, Susan;Colaizzi, Paul;Kim, Youngjin;Jeon, Jonggil;Lee, Sangbong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.61 no.6
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    • pp.111-121
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    • 2019
  • Evapotranspiration (ET) of vegetation is one of the major components of the hydrologic cycle, and its accurate estimation is important for hydrologic water balance, irrigation management, crop yield simulation, and water resources planning and management. For agricultural crops, ET is often calculated in terms of a short or tall crop reference, such as well-watered, clipped grass (reference crop evapotranspiration, $ET_o$). The Penman-Monteith equation recommended by FAO (FAO 56-PM) has been accepted by researchers and practitioners, as the sole $ET_o$ method. However, its accuracy is contingent on high quality measurements of four meteorological variables, and its use has been limited by incomplete and/or inaccurate input data. Therefore, this study evaluated the applicability of Backpropagation Neural Network (BPNN) model for estimating $ET_o$ from less meteorological data than required by the FAO 56-PM. A total of six meteorological inputs, minimum temperature, average temperature, maximum temperature, relative humidity, wind speed and solar radiation, were divided into a series of input groups (a combination of one, two, three, four, five and six variables) and each combination of different meteorological dataset was evaluated for its level of accuracy in estimating $ET_o$. The overall findings of this study indicated that $ET_o$ could be reasonably estimated using less than all six meteorological data using BPNN. In addition, it was shown that the proper choice of neural network architecture could not only minimize the computational error, but also maximize the relationship between dependent and independent variables. The findings of this study would be of use in instances where data availability and/or accuracy are limited.