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Effect of Dose Rate Variation on Dose Distribution in IMRT with a Dynamic Multileaf Collimator (동적다엽콜리메이터를 이용한 세기변조방사선 치료 시 선량분포상의 선량률 변화에 따른 효과)

  • Lim, Kyoung-Dal;Jae, Young-Wan;Yoon, Il-Kyu;Lee, Jae-Hee;Yoo, Suk-Hyun
    • The Journal of Korean Society for Radiation Therapy
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    • v.24 no.1
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    • pp.1-10
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    • 2012
  • Purpose: To evaluate dose distribution differences when the dose rates are randomly changed in intensity-modulated radiation therapy using a dynamic multileafcollimator. Materials and Methods: Two IMRT treatment plans including small-field and large-field plans were made using a commercial treatment planning system (Eclipse, Varian, Palo Alto, CA). Each plan had three sub-plans according to various dose rates of 100, 400, and 600 MU/min. A chamber array (2D-Array Seven729, PTW-Freiburg) was positioned between solid water phantom slabs to give measurement depth of 5 cm and backscattering depth of 5 cm. Beam deliveries were performed on the array detector using a 6 MV beam of a linear accelerator (Clinac 21EX, Varian, Palo Alto, CA) equipped with 120-leaf MLC (Millenium 120, Varian). At first, the beam was delivered with same dose rates as planned to obtain reference values. After the standard measurements, dose rates were then changed as follows: 1) for plans with 100 MU/min, dose rate was varied to 200, 300, 400, 500 and 600 MU/min, 2) for plans with 400 MU/min, dose rate was varied to 100, 200, 300, 500 and 600 MU/min, 3) for plans with 600 MU/min, dose rate was varied to 100, 200, 300, 400 and 500 MU/min. Finally, using an analysis software (Verisoft 3.1, PTW-Freiburg), the dose difference and distribution between the reference and dose-rate-varied measurements was evaluated. Results: For the small field plan, the local dose differences were -0.8, -1.1, -1.3, -1.5, and -1.6% for the dose rate of 200, 300, 400, 500, 600 MU/min, respectively (for 100 MU/min reference), +0.9, +0.3, +0.1, -0.2, and -0.2% for the dose rate of 100, 200, 300, 500, 600 MU/min, respectively (for 400 MU/min reference) and +1.4, +0.8, +0.5, +0.3, and +0.2% for the dose rate of 100, 200, 300, 400, 500 MU/min, respectively (for 600 MU/min reference). On the other hand, for the large field plan, the pass-rate differences were -1.3, -1.6, -1.8, -2.0, and -2.4% for the dose rate of 200, 300, 400, 500, 600 MU/min, respectively (for 100 MU/min reference), +2.0, +1.8, +0.5, -1.2, and -1.6% for the dose rate of 100, 200, 300, 500, 600 MU/min, respectively (for 400 MU/min reference) and +1.5, +1.9, +1.7, +1.9, and +1.2% for the dose rate of 100, 200, 300, 400, 500 MU/min, respectively (for 600 MU/min reference). In short, the dose difference of dose-rate variation was measured to the -2.4~+2.0%. Conclusion: Using the Varian linear accelerator with 120 MLC, the IMRT dose distribution is differed a little <(${\pm}3%$) even though the dose-rate is changed.

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The Change of Blink Rate by Wearing Soft Contact Lens (소프트콘택트렌즈 착용에 의한 순목 횟수 변화)

  • Lee, Youn-Jin;Park, Sang-Il;Lee, Heum-Sook;Park, Mi-Jung
    • Journal of Korean Ophthalmic Optics Society
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    • v.11 no.3
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    • pp.173-179
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    • 2006
  • We investigated the change of the blink rate by wearing soft contact lens(SCL). Eight types of soft contact lenses were worn by twelve asymptomatic contact lens wearers. When wearers were worn SCLs for 15 min, the average blink rate was 20.0 blinks/min, which was a statistically significant increase compared to 13.3 blinks/min, the average blink rate of non-SCL-worn eye. After 8 hr of lens wear, the average blink rate was 24.3 blinks/min, and it was 11 blinks/min more than that of non-SCL-worn eye and 4 blinks/min more than that of 15 min SCL-worn eye. There were a little difference of the blink rate in types of lens, which the blink rate range of all lens after 15 min of lens wear was 18.1~20.9 blinks/min and that after 8 hr of lens wear was 22.9~24.9 blinks/min. When wearing A lens(vifilcon, 0.06 mm) having thin center thickness, wearers showing difference of 10.0~11.9 blinks/min between non-SCL-worn eye and 15 min SCL-worn eye reached 16.7% and it was more than that of relatively thick B lens(0.17 mm) and C lens(0.14 mm). This result suggest that the center thickness was not unique factor of the blink rate change and other factors would have synthetically influence on the blink rate change. In the case of B lens and C lens of hilafilcon material but having different center thickness and water content, wearers increasing more than 4.0 blinks/min after 8 hr of lens wear was 58.3% and 41.7%, respectively. This result have provided information that the lenses of similar materials but different center thickness and water content could cause individually the different change of the blink rate.

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The Mean Transit Time of the CBD and the Afferent Loop Using $^{99m}Tc-DISIDA$ Scintigram in Truncal Vagotomy (미주신경간절제술에 있어서 $^{99m}Tc-DISIDA$ 신티그램을 이용한 총수담관 및 Afferent loop의 평균지연시간)

  • Moon, Tae-Yong;Kim, Dong-Soo
    • The Korean Journal of Nuclear Medicine
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    • v.22 no.2
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    • pp.199-203
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    • 1988
  • The authors observed functional change of the CBD and the afferent loop with the transit time of $^{99m}Tc-DISIDA$ scintigram in patients treated by the surgical operation of gastric ulcers and cancer at Busan National University Hospital from June, 1987 to April, 1988. So authors estimated the time between the peak activity of the CBD and the afferent loop (TCA), the half transit time of the CBD activity (t 1/2 CBD) and the half transit time of the afferent loop activity (t 1/2 A-loop) in 9 patients undergone truncal vagotomy, who have no specific symptoms at 2 to 6 months after the operation, 5 patients undergone the operation without truncal vagotomy, and 7 persons as a control group. The results were as follows: I) In control group, the mean TCA, t 1/2 CBD and t 1/2 duodenum were $8.6{\pm}9.0$ min, $38.7{\pm}17.3$ min. and $28.6{\pm}10.9$ min, respectively. 2) In the operation group without truncal vagotomy, the mean TCA, t 1/2 CBD and t 1/2 A-loop were $10.0{\pm}7.1$ min. $48.2{\pm}22.3$ min. and $39.4{\pm}26.7$ min. respectively. 3) In the operation group with truncal vagotomy, the mean TCA, t 1/2 CBD and t 1/2 A-loop were $15.0{\pm}8.7$ min., $36.1{\pm}16.5$ min. and $42.6{\pm}24.4$ min, respectively. From the above results, we concluded that the transit time of the CBD and the afferent loop is not affected by truncal vagotomy.

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Prediction of Extration Conditions for the Optimized Organoleptic Quality of Eucommia ulmoides Leaf-tea (두충차의 관능적 품질에 대한 최적 추출조건의 예측)

  • 권중호;김만배;이기동;정용진;이명희;이성태
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.5
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    • pp.914-919
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    • 1998
  • This work was designed to determine the optimum extraction conditions for imporving the quality of Eucommia ulmoidesl leaf-tea. Soluble solid content was 27.7% in the tea extracted at 99.3$^{\circ}C$(extraction temperature) and 67.8 min(extraction time) which were maximum points by the ridge analysis. The extraction conditions for the maximum organoleptic scores were 72.9$^{\circ}C$ and 59.6 min in color, 80.$0^{\circ}C$ and 90.0 min in aroma, 77.8$^{\circ}C$ and 55.5 min in aftertaste, and 77.9$^{\circ}C$ and 53.1 min in overall palatability. The extraction conditions for the minimum organoleptic scores were 77.8$^{\circ}C$ and 52.7 min in astringent taste, and 75.1$^{\circ}C$ and 49.4 min in Chinese medicine taste. The optimum ranges of the conditions based on soluble solid content and overall palatability of the tea wre 75~83$^{\circ}C$ and 55~65 min. The soluble solid content and overall palatability predicted at ooptimum condition(78$^{\circ}C$ and 60 min) werw similar to experimental values.

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Monitoring the Functional Properties of Pleurotus eryngii Extracts Using Response Surface Methodology

  • Oh, Hyun-In;Lim, Tae-Soo;Lee, Gee-Dong;Kim, Hyun-Ku
    • Food Science and Biotechnology
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    • v.16 no.2
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    • pp.299-305
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    • 2007
  • Response surface methodology was employed to optimize extraction conditions for finding the maximal functional properties of Pleurotus eryngii. Based on central composite design, the study plan was established with variations of microwave power (30-150 W), ethanol concentration (0-99.9%), and extraction time (1-9 min). Regression analysis was applied to obtain a mathematical model. A maximal yield of 47.86% was obtained when the microwave power, ethanol concentration, and extraction time were set at 122.7 W, 42.14%, and 8.3 min, respectively. A maximized electron donating ability of 93.32% was found under the following conditions: a microwave power of 144.19 W, an ethanol concentration of 49.52%, and an extraction time of 6.7 min. When the microwave power, ethanol concentration, and extraction time were set at 125.43 W, 40.54%, and 8.1 min, respectively, the maximum nitrite-scavenging ability was 80.47%. The optimum ranges of the extraction conditions, superimposed by the response surface methodology, could predicate a microwave power of 110-150 W, ethanol concentration of 0-45%, and extraction time of 7-9 min.

Preparation of Barley Leaf Powder Tea and Its Quality Characteristics (보리잎 분말차의 제조와 그 품질특성)

  • Kim, Dong-Chung;Kim, Dong-Won;Lee, Sung-Dong;In, Man-Jin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.6
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    • pp.734-737
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    • 2006
  • This study was carried out to establish the manufacturing process of barley leaf powder tea. The optimal manufacturing process among many trials was determined with sensory evaluation. Finally established process and operation conditions were as follows: pretreatment (cutting and washing), steaming ($100^{\circ}C$, 30 sec), primary drying and roasting ($130^{\circ}C$, 40 min), rolling (RT, 25 min), middle drying and roasting ($60^{\circ}C$, 30 min), final drying and roasting ($55^{\circ}C$, 25 min), drying ($60^{\circ}C$, 20 min), roasting ($85^{\circ}C$, 20 min), and powdering (120 mesh). The barley leaf powder tea produced by this process mainly consisted of dietary fiber (33.8%), amino acids (12.9%), minerals (4.7%) and ${\beta}-carotene$ (6.9 mg%).

Heat Resistance Studies of Selected Yeasts Isolated from Swollen Commerically Canned Peaches (부패된 복숭아 통조림으로부터 분리된 효모의 열저항성에 관한 연구)

  • Choi, Jeong-Yi;Park, Seung-Kyu;Kyung, Kyu-Hang
    • Korean Journal of Food Science and Technology
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    • v.19 no.1
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    • pp.38-41
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    • 1987
  • This investigation was to measure heat resistance (D and Z values) of ascospores of Saccharomyces cerevisiae Py9 and Saccharomyces chevalieri Pw7 isolated from swollen commercially canned peaches. Decimal reduction times (D values) of S. cerevisiae Py9 ascospores were 6.5 min at $58^{\circ}C$, 2.5 min at $60^{\circ}C$ and 1.25 min at $62^{\circ}C$. Those of S chevalieri Pw7 ascospores were 35.0 min at $58^{\circ}C$ 3.5min at $60^{\circ}C$ and 1.5 min at $62^{\circ}C$ Zvalues of S. cerevisiae and S. chevalienri ascospores were $5.5^{\circ}C$ and $3.4^{\circ}C$, respectively.

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Influence of Dry Roasting of Whole Faba Beans (Vicia faba) on Rumen Degradation Characteristics in Dairy Cows, II: Starch

  • Yu, P.;Egan, A.R.;Holmes, J.H.G.;Leury, B.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.11 no.5
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    • pp.503-509
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    • 1998
  • Whole faba beans (WFB) were dry roasted at different temperatures of 110, 130 and $150^{\circ}C$ for 15, 30 and 45 minutes (min) to determine the optimal heating conditions to increase bypass starch as glucose source which may be a limiting nutrient in high producing dairy cattle. Ruminant degradation characteristics of starch (St) of WFB were determined using in sacco method in 6 dairy cows fed 60% hay and 40% concentrate. Measured characteristics of St were soluble (washable) fraction (S), potentially degradation fraction (D) and the rate of degradation (Kd) of the insoluble but degradable St fraction. Based on measurement of these characteristics, percentage bypass starch (%BSt) and bypass starch (BSt) were calculated. Degradability of starch in the rumen was reduced by dry roasting at temperature of 130 and $150^{\circ}C$ and increased at $110^{\circ}C$. S varied from 50.0% in the raw whole faba beans (RWFB) and 53.7% in $110^{\circ}C$/15 min to 18.2% in $150^{\circ}C$/45 min. D varied from 49.9% in RWFB and 46.3% in $110^{\circ}C$/15 min to 81.8 % in $150^{\circ}C$/45 min. Kd varied from 9.8% in RWFB and 11.0% in the $110^{\circ}C$/30 min to 4.2 in $150^{\circ}C$/45 min. All these effects resulted in increasing %BSt from 22.1% in the $110^{\circ}C$/45 min and 23.9% in RWFB to 49.9% in the $150^{\circ}C$/45 min. Therefore BSt increased from 91.4 g/kg and 98.4 g/kg to 199.9 g/kg respectively. Dry roasting at $110^{\circ}C$ increased the starch rumen degradation. Treatment at higher temperature (130 and $150^{\circ}C$) decreased rumen degradation of starch and seemed to be linear up to highest values tested. No optimal dry roasting conditions of treatment could be determined at this stage. It may be concluded that dry roasting at temperatures of 130 and $150^{\circ}C$ was effective in shifting starch degradation from rumen to intestine to increase bypass starch.

Reproductive Behavior of the Barn Swallow (Hirundo rustica) in Korea - A Case Study in Gwangju Metropolitan City - (한국에 도래하는 제비(Hirundo rustica)의 번식행동 - 광주광역시를 사례로 -)

  • Kim, Sang-jin;Oh, Hong-shik
    • Korean Journal of Environment and Ecology
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    • v.31 no.2
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    • pp.127-134
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    • 2017
  • This study was conducted to identify the reproductive behavior of the barn swallow. The study was carried out in Gwangju, Korea during the 2013 breeding season. In the morning, the nest-building frequency was 14.2~31.0 trips/h (10.2~19.8 trips/h by male and 4.0~11.4 trips/h by female). The nest-building activity took 7.6~15.9 min/h (4.8~8.1 min/h by male and 2.8~8.0 min/h by female). The nest-building time by female ($40.0{\pm}27.9sec/trip$) was about 1.5 times longer than the nest-building time by male ($26.1{\pm}15.5sec/trip$). Only the female incubated the eggs. The Incubation time was $50.6{\pm}17.5min/h$ (84%) at 6h, 24.5 min/h (40.8%) at 7h and 15.6 min/h (26.0%) thereafter. During daytime, the female incubation time showed a highly significant difference (p<0.001), and the incubation time at 6h was higher than that at other times. There was a significantly negative correlation between female incubation time and the mean air temperature(p<0.05). The frequency of feeding was $385.2{\pm}66.9trips/nest$ in the daytime ($219.2{\pm}37.1trips/nest$ by male and $166.0{\pm}30.8trips/nest$ by female). The frequency of feeding per hour was $32.1{\pm}12.3trips/h$ ($18.3{\pm}7.8trips/h$ by male and $14.3{\pm}4.5trips/h$ by female). The frequency of feeding per hour showed a significant difference in the range of 10h(p<0.05) and 15h(p<0.01) by sex. The time of feeding by female ($40.9{\pm}83.3sec/trip$) was longer than the time of feeding by male ($12.3{\pm}31.0sec/trip$). The juvenile defecation frequency was $45.6{\pm}8.4times/nest$ per day and showed a positive correlation with feeding frequency (p<0.05). The results of this study will be helpful in understanding the reproductive behaviors of the swallow adapted to the environment in Korea.