• The Journal of Korean Society for Radiation Therapy
• /
• v.19 no.1
• /
• pp.51-54
• /
• 2007

Purpose: Total body irradiation is used to kill the total malignant cell and for immunosuppression component of preparatory regimens for bone-marrow restitution of patients. Beam spoiler is used to increase the dose to the superficial tissues. This paper finds the property of the distance between beam spoiler and patient. Materials and Methods: Set-up conditions are 6 MV-Xray, 300 MU, SAD = 400 cm, field size = $40{\times}40cm^2$. The parallel plate chamber located in surface, midpoint and exit of solid water phantom. The surface dose is measured while the distance between beam spoiler and patient is altered. Because it should be found proper distance. The solid water phantom is fixer and beam spoiler is moving. Results: Central dose of phantom is 10.7 cGy and exit dose is 6.7 cGy. In case of distance of 50 cm to 60 cm between beam spoiler and solid water phantom, incidence dose is $14.58{\sim}14.92cGy$. Therefore, The surface dose was measured $99.4{\sim}101%$ with got near most to the prescription dose. Conclusion: In clinical case, distance between beam spoiler and patient affect surface dose. If once $50{\sim}60cm$ of distance between beam spoiler and patient, surface dose of patient got near prescription dose. It would be taken distance between beam spoiler and patient into account in clinical therapy.

• Journal of the Korean Applied Science and Technology
• /
• v.36 no.4
• /
• pp.1312-1326
• /
• 2019

The purpose of this study is to examine whether the 12-week Nordic walking can improve the physical function and arthritis pain of elderly women with osteoarthritis This study were divided into randomly assigned Nordic Walking Exercise Group (n=9) and Control Group (n=7) for 16 Elderly women diagnosed with Osteoarthritis (age: 73±3.79 year, height: 154.3±4.09 cm). The exercise group used Nordic sticks to carry out 30 minutes of Nordic walking exercise three times a week for 12 weeks, and the kinetic intensity was set at 40-60% of HRR. The control group maintained daily life for the same period. Body composition (weight, percentage body fat, skeletal muscle mass), muscular strength, Flexibility (muscular strength of upper and lower limbs, flexibility of upper and lower limbs), balance ability (static balance, dynamic balance) and pain level were measured as subordinate variables. These indicators were measured twice before and after the exercise program. The study shows that percentage body fat and skeletal muscle mass in the body composition function over 12 weeks of Nordic walking exercise have significant effects after the exercise than before (p=004)(p=.003), and it also shows significant interaction effects between the groups and timings(p=.018)(p=.005). In muscular strength, Flexibility factors, there were significant effects between the groups and timings in the upper limb muscular strength and the lower limb flexibility (p=.009)(p=.036), and a significant difference between the exercise group and the control group(p=.006) in the lower limb muscular strength. In addition, in the upper limb flexibility, there was a more significant difference after the exercise than before(p=.020). There were improvement effects after the exercise than before in the balance ability and the static balance(p=.016), but no difference in the dynamic balance(p>.05). In pain, there was a significant improvement after the exercise than before(p=.022), and a significant difference between the exercise group and the control group(p=.013). In conclusion, the 12-week Nordic walking exercise has positive effects on the body composition functions of the elderly women with Osteoarthritis, and has a positive effect on the improvement of upper limb muscular strength and lower limb flexibility in the health fitness factors. These effects are believed to have contributed effectively to the improvement of the level of pain by contributing to the improvement of physical and motor functions of the elderly women with Osteoarthritis. Therefore, it is considered that Nordic walking exercise, which enhances stability and balance of the patients with Osteoarthritis by using poles, is an effective exercise method for the improvement of the body and motor functions by lowering the pain of the joints and reducing the muscular strength and percentage body fat.

• Microbiology and Biotechnology Letters
• /
• v.48 no.3
• /
• pp.344-357
• /
• 2020

Strain improvement and bioprocess development were undertaken to enhance hyaluronic acid(HA) production by Streptococcus zooepidemicus cells. Using a high-yielding mutant strain, statistical medium optimization was carried out in shake flask cultures, resulting in 52% increase in HA production (5.38 g/l) at the optimal medium composition relative to the parallel control cultures. For sufficient supply of dissolved oxygen (DO), which turned out to be crucial for enhanced production of HA, agitation system and speed were intensively investigated in 5 L bioreactor cultures. Increase in oxygen mass transfer coefficient (k_La) through increment of agitation speed (rpm) and 35% expansion of diameter of the newly-designed impellers showed significantly positive effects on HA production. By installing an expanded Rushton-turbine impeller for efficient break-down of sparged air, and an extended marine impeller above the Rushton-turbine impeller for efficient mixing of the air-born viscous fermentation broth, maximum amount of HA (9.79 g/l) was obtained at 450 rpm, 1.8 times higher level than that of the corresponding flask culture. Subsequently, the possibility of bioprocess scale-up to a 50 L bioreactor was investigated. Despite almost identical maximum HA production (9.11 vs 9.25 g/l), the average HA volumetric productivity (r_p) of the 50 L culture turned out only 74% compared to the corresponding 5 L culture during the exponential phase, possibly caused by shear damages imposed on the producing cells at the high stirring in the 50 L culture. The scale-up process could be successfully achieved if a scale-up criterion of constant oxygen mass transfer coefficient (k_La) is applied to the 50 L pilot-scale bioreactor system.

• The Journal of Korean Society for Radiation Therapy
• /
• v.27 no.1
• /
• pp.53-60
• /
• 2015

Purpose : The purpose of this study is to evaluate the usefulness of a 3D printed phantom for in-vivo dosimetry of a prostate cancer patient. Materials and Methods : The phantom is produced to equally describe prostate and rectum based on a 3D volume contour of an actual prostate cancer patient who is treated in Asan Medical Center by using a 3D printer (3D EDISON+, Lokit, Korea). CT(Computed tomography) images of phantom are aquired by computed tomography (Lightspeed CT, GE, USA). By using treatment planning system (Eclipse version 10.0, Varian, USA), treatment planning is established after volume of a prostate cancer patient is compared with volume of the phantom. MOSFET(Metal OXIDE Silicon Field Effect Transistor) is estimated to identify precision and is located in 4 measuring points (bladder, prostate, rectal anterior wall and rectal posterior wall) to analyzed treatment planning and measured value. Results : Prostate volume and rectum volume of prostate cancer patient represent 30.61 cc and 51.19 cc respectively. In case of a phantom, prostate volume and rectum volume represent 31.12 cc and 53.52 cc respectively. A variation of volume between a prostate cancer patient and a phantom is less than 3%. Precision of MOSFET represents less than 3%. It indicates linearity and correlation coefficient indicates from 0.99 ~ 1.00 depending on dose variation. Each accuracy of bladder, prostate, rectal anterior wall and rectal posterior wall represent 1.4%, 2.6%, 3.7% and 1.5% respectively. In- vivo dosimetry represents entirely less than 5% considering precision of MOSFET. Conclusion : By using a 3D printer, possibility of phantom production based on prostate is verified precision within 3%. effectiveness of In-vivo dosimetry is confirmed from a phantom which is produced by a 3D printer. In-vivo dosimetry is evaluated entirely less than 5% considering precision of MOSFET. Therefore, This study is confirmed the usefulness of a 3D printed phantom for in-vivo dosimetry of a prostate cancer patient. It is necessary to additional phantom production by a 3D printer and In-vivo dosimetry for other organs of patient.

• The Journal of Korean Society for Radiation Therapy
• /
• v.31 no.2
• /
• pp.75-81
• /
• 2019

Purpose: Tomo therapy and Proton therapy treatment plans for the treatment of prostate cancer patients were established, and the characteristics of dose distribution according to beam delivery method using Tomo therapy IMRT method and Proton therapy PBS method to compare and analyze the treatment effect were sought. Materials and Methods: Tomo IMRT treatment plan and Proton PBS treatment plan were established using the Hi.art planning station 5.1.1.6 of Tomo therapy and Eclipse 13.7 of VARIAN for three prostate cancer patients who were treated with radiotherapy only for radical purposes without surgery. For the evaluation of two treatment plans, the average dose (Dmean) and maximum dose (Dmax) of PGTV were calculated from dose volume histogram (DVH) to confirm the coverage and calculate CI and HI. In OAR evaluation, the dose received from the rectal volume 25% and the dose received from the bladder were evaluated to compare the normal long-term protection effect. Results: The mean maximum doses of the three patients were 71.4Gy, 75.3Gy and the mean doses were 70.4Gy and 72.8Gy in the DVH of the Tomo IMRT and Proton PBS. The CI was 1.16 and 1.31, and the HI was 0.04 and 0.12 respectively, and the Tomo IMRT was superior to the Proton PBS in dose suitability. Conclusion: The mean dose of PGTV in prostate cancer patients was 3.4% higher in Proton PBS than in Tomo IMRT. This is because the Dose suitability of Tomo IMRT was better, but it is considered to be a small difference to be seen as a significant result. However, the results of the two methods were 51.2% in D 25% and 55.7% less in the average dose of bladder, which could reduce the side effects of patients in proton PBS.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.5
• /
• pp.596-607
• /
• 2017

This study examined the method for adding related to "stomach neoplasms" as filters to the Medical Subject Headings (MeSH) for search as well as a method for improving the search efficiency through a word-proximity search by measuring the distance of co-occurring terms. A total of 8,625 articles published between 2007 and 2016 with the major topic terms "stomach neoplasms" were downloaded from PubMed article titles. The vocabulary to be added to the MeSH for search were analyzed. The search efficiency was verified by 277 articles that had "Stomach Neoplasms" indexed as MEDLINE MeSH in KoreaMed. As a result, 973 terms were selected as the candidate vocabulary. "Gastric Cancer" (2,780 appearances) was the most frequent term and 7,376 compound words (88.51%) combined the histological terms of "stomach" and "neoplasm", such as "gastric adenocarcinoma" and "gastric MALT lymphoma". A total of 5,234 compounds words (70.95%), in which the co-occurring distance was two words, were found. The matching rate through the MEDLINE MeSH and KoreaMed MeSH Indexer was 209 articles (75.5%). The search efficiency improved to 263 articles (94.9%) when the search filters were added, and to 268 articles (96.7%) when the 13 word-proximity search technique of the co-occurring terms was applied. This study showed that the use of a thesaurus as a means of improving the search efficiency in a natural language search could maintain the advantages of controlled vocabulary. The search accuracy can be improved using the word-proximity search instead of a Boolean search.

• Journal of radiological science and technology
• /
• v.32 no.2
• /
• pp.183-194
• /
• 2009

Purpose : This study was performed not only to compare the brain activation regions associated with sexual arousal induced by visual stimulation and SP6 acupuncture, but also to evaluate its differential neuro-anatomical mechanism in healthy women using functional magnetic resonance imaging (fMRI) at 3 Tesla (T). Subjects and methods : A total of 21 healthy right-handed female volunteers (mean age 22 years, range 19 to 32) underwent fMRI on a 3T MR scanner. The stimulation paradigm for sexual arousal consisted of two alternating periods of rest and activation. It began with a 1-minute rest period, 3 minutes of stimulation with either of an erotic video film or SP6 acupuncture, followed by 1-minute rest. In addition, a comparative study on the brain activation patterns between an acupoint and a shampoint nearby GB37 was performed. The fMRI data were obtained from 20 slices parallel to the AC-PC line on an axial plane, giving a total of 2,000 images. The mean activation maps were constructed and analyzed by using the statistical parametric mapping (SPM99) software. Results : As comparison with the shampoint, the acupoint showed 5 times and 2 times higher activities in the neocortex and limbic system, respectively. Note that brain activation in response to stimulation with the shampoint was not observed in the regions including the HTHL in the diencephalon, GLO and AMYG in the basal ganglia, and SMG in the parietal lobe. In the comparative study of visual stimulation vs. SP6 acupuncture, the mean activation ratio of stimulus was not significantly different to each other in both the neocortex and the limbic system (p < 0.05). The mean activities induced by both stimuli were not significantly different in the neocortex, whereas the acupunctural stimulation showed higher activity in the limbic system (p < 0.05). Conclusions : This study compared the differential brain activation patterns and the neural mechanisms for sexual arousal, which were induced by visual stimulation and SP6 acupuncture by using 3T fMRI. These findings will be useful to understand the theory of traditional acupuncture and acupoint channel in scientific point of view.

• Journal of Korean Home Economics Education Association
• /
• v.21 no.2
• /
• pp.139-158
• /
• 2009

The purposes of this study are to develop cyber home study program on consumer life for youth in middle school students and to compare the learning effect of this program with that of teacher's off-line lecture in class. The contents of the middle school Home Economics. Technology textbooks was analyzed. Based on this analysis 4 cyber home study lesson plans on youth's consumer life were developed. The topics of lesson plan were as 'youth and consumer behavior', 'utilizing consumer information'. 'effective consumer choice', 'resolving consumer problems'. The cyber home study were composed of 5 steps which were 'guiding' $\rightarrow$ 'learning activities' $\rightarrow$ 'evaluation' $\rightarrow$ 'further study' $\rightarrow$ 'summery'. The second grade middle school students as an experimental group participated in cyber home study through on-line class. The control group of students who had same condition with the experimental group were taught by home economics teacher using traditional instructional methods in off-line class. After the experiment, the changes in consumer's attitudes and knowledge of both groups were analyzed using Analysis of Covariance. The significant improvements of consumer's attitudes and knowledge were found in both the experimental and control groups of students. However, the consumer's attitudes and knowledge of the students who were taught by the teacher in off-line class improved more than those of the students who studied using cyber home study program in on-line class. Thus, the following conclusion is made that the cyber home study could be one of the useful learning methods to aid traditional off-line teaching in class.

• Journal of The Korean Association For Science Education
• /
• v.34 no.7
• /
• pp.677-691
• /
• 2014

Understanding of the nature of science (NOS) has been a consistent topic as one of the most important goals in science education for the past several decades. Even though there is a variety of research related with the NOS conducted in science education, few researches has been conducted for the conception of scientists regards to the nature of science (Bayir et al., 2014; Taylor et al., 2008; Wong & Hudson, 2008). Recently, researchers in science education turned their attention to identifying views of scientists about the nature of science since they recognized the importance of participation of scientists in science education (Southerland et al., 2003; Taylor et al., 2008). This study was conducted to examine the Korean scientists' views of the nature of science. Through the use of semi-structured questionnaire and in-depth interview the views of 35 scientists who belong to the Korean-American Scientists and Engineers Association (KSEA) regards to the nature of science were explored. Findings show that while the scientists have more informed views with respect to the tentativeness of scientific knowledge, cultural and social influence embedded in science, the limitation of science, and the collaboration of science with others, the scientists have more na${\ddot{i}}$ve views about the distinction between laws and theories, the existence of a universal scientific method, and the importance of imagination and creativity. As such, it can be assumed that the scientists cannot conceptualize their notion in a philosophical sense even though they are engaged in scientific work in reality (Bayir et al., 2014).

• Journal of Dental Rehabilitation and Applied Science
• /
• v.24 no.2
• /
• pp.213-230
• /
• 2008

The aim of this study was to analyze the initial movement and the stress distribution of each tooth and periodontal ligament during the lingual lever-arm retraction of 6 maxillary incisors using FEA. Two kinds of finite element models were produced: 2-properties model (simple model) and 24-properties model (multi model) according to the material property assignment. The subject was an adult male of 23 years old. The DICOM images through the CT of the patient were converted into the 3D image model of a skull using the Mimics (version 10.11, Materialise's interactive Medical Image Control System, Materialise, Belgium). After series of calculating, remeshing, exporting, importing process and volume mesh process was performed, FEA models were produced. FEA models are consisted of maxilla, maxillary central incisor, lateral incisor, canine, periodontal ligaments and lingual traction arm. The boundary conditions fixed the movements of posterior, sagittal and upper part of the model to the directions of X, Y, Z axis respectively. The model was set to be symmetrical to X axis. Through the center of resistance of maxilla complex, a retraction force of 200g was applied horizontally to the occlusal plane. Under this conditions, the initial movements and stress distributions were evaluated by 3D FEA. In the result, the amount of posterior movement was larger in the multi model than in the simple model as well as the amount of vertically rotation. The pattern of the posterior movement in the central incisors and lateral incisors was controlled tipping movement, and the amount was larger than in the canine. But the amount of root movement of the canine was larger than others. The incisor rotated downwardly and the canines upwardly around contact points of lateral incisor and canine in the both models. The values of stress are similar in the both simple and multi model.