• Title/Summary/Keyword: Radiation dosage

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Effects of Gamma Irradiation on the Extraction Yield and Whitening Activity of Polysaccharides from Undaria pinnatifida Sporophyll (감마선 조사가 미역귀 조다당의 추출수율 및 미백활성 변화에 미치는 영향)

  • Kim, Da-Mi;Kim, Kyoung-Hee;Sung, Nak-Yun;Jung, Pil-Moon;Kim, Jeong-Soo;Kim, Jae-Kyung;Kim, Jae-Hun;Choi, Jong-Il;Song, Beom-Seok;Lee, Ju-Woon;Kim, Jin-Kyu;Yook, Hong-Sun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.5
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    • pp.712-716
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    • 2011
  • We investigated changes in the extraction yield and whitening activity of polysaccharides from Undaria pinnatifida sporophyll due to gamma irradiation. U. pinnatifida sporophyll was gamma-irradiated at doses of 10, 30, 50, 70, and 100 kGy, then extracted with hot water and precipitated with ethanol to extract polysaccharides. Crude polysaccharide yields increased with an increase in irradiation dosage, but tyrosinase inhibition activity did not change. Melanin synthesis did not significantly differ between B16BL6 cells treated with irradiated and non-irradiated samples. In conclusion, gamma irradiation increased the crude polysaccharide extraction yield but did not change the whitening activity of U. pinnatifida sporophyll. This implies that gamma irradiation can be used to increase yields in the cosmetic industry, thus increasing profits.

Effects of Antioxidant and Thermal Treatment on the Radiation Resistance of Polypropylene (폴리프로필렌의 내방사선성에 미치는 산화방지제와 열처리의 영향)

  • Park Sung Hyun;Kim Hyung-Il;Kang Phil Hyun;Nho Young Chang
    • Polymer(Korea)
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    • v.30 no.1
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    • pp.10-13
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    • 2006
  • The effects of antioxidants and thermal treatment on the radiation resistance of the gamma-ray irradiated polypropylene (PP) were studied. The PP was blended with various antioxidants and was fabricated into a sheet. The PP sheet was irradiated with gamma-ray to a dosage of 25kGy in the nitrogen atmosphere. The differences in both color and mechanical strength were investigated for the gamma-ray irradiated PP depending on the kind and the content of antioxidant. The residual amount of free radical and the variation of oxidation index were investigated for the gramma-ray irradiated PP with thermal treatment after irradiation. The PP having phosphite antioxidant showed little difference in color after gamma-ray irradiation compared with the PP having phenolic or mine antioxidant. Sufficient amount of free radical could be removed from the gamma-ray irradiated PP by the thermal treatment at $130\;^{\circ}C$ for 30 min. Thermally treated PP showed lower oxidation index than the PP without thermal treatment.

Reference X-ray Irradiation System for Personal Dosimeter Testing and Calibration of Radiation Detector

  • Lee, Seung Kyu;Chang, Insu;Kim, Sang In;Lee, Jungil;Kim, Hyoungtaek;Kim, Jang-Lyul;Kim, Min Chae
    • Journal of Radiation Protection and Research
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    • v.44 no.2
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    • pp.72-78
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    • 2019
  • Background: In the calibration and testing laboratory of Korea Atomic Energy Research Institute, the old X-ray generator used for the production of reference X-ray fields was replaced with a new one. For this newly installed X-ray irradiation system, beam alignment as well as the verification of beam qualities was conducted. Materials and Methods: The existing X-ray generator, Phillips MG325, was replaced with YXLON Y.TU 320-D03 in order to generate reference X-ray fields. Theoretical calculations and Monte Carlo simulations were used to determine initial filter thickness. Beam alignment was performed in three steps to deliver a homogeneous radiation dosage to the target at different distances. Finally, the half-value layers were measured for different X-ray fields to verify beam qualities by using an ion chamber. Results and Discussion: Beam alignment was performed in three steps, and collimators and other components were arranged to maintain the uniformity of the mean air kerma rate within ${\pm}2.5%$ at the effective beam diameter of 28 cm. The beam quality was verified by using half-value layer measurement methods specified by American National Standard Institute (ANSI) N13.11-2009 and International Organization for Standardization (ISO)-4037. For each of the nine beams than can be generated by the new X-ray irradiation system, air kerma rates for X-ray fields of different beam qualifies were measured. The results showed that each air kerma rate and homogeneity coefficient of the first and second half-value layers were within ${\pm}5%$ of the recommended values in the standard documents. Conclusion: The results showed that the new X-ray irradiation system provides beam qualities that are as high as moderate beam qualities offered by National Institute of Standards and Technology in ANSI N13.11-2009 and those for narrow-spectrum series of ISO-4037.

Effects of UV-B Radiation and Water Stress on Hardening Phase Growth of Container-Grown Betula platyphylla Seedlings (자작나무 콘테이너묘(苗)의 경화단계(硬化段階) 생장(生長)에 미치는 UV-B 와 수분(水分)스트레스의 효과(效果))

  • Kim, Jong Jin;Hong, Sung Gak
    • Journal of Korean Society of Forest Science
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    • v.87 no.4
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    • pp.601-610
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    • 1998
  • This study was carried out to investigate the possibility of supplemental UV-B application to the hardening phase of container-grown Betula platyphylla seedlings. The containerized seedlings were grown in a growth chamber for four months and then treated with UV-B(UV-$B_{BE}$ $3.2KJ\;m^{-2}\;day^{-1}$ and $5.2KJ\;m^{-2}\;day^{-1}$) radiation and water stress regime(irrigation in one week interval) for four weeks. The differences in growth and physiological responses of the seedlings before and after the treatments were analyzed. UV-B radiation and water stress reduced height growth and leaf dry mass accumulation of the seedlings. The root collar diameter growth was reduced by UV-B radiation but increased by water stress. The reduction in leaf dry weight by UV-B radiation and water stress reduced T/R ratio of the seedling. The reduction in T/R ratio was the most apparent by water stress. Chlorophyll index observed by a chlorophyll meter was the lowest in the $5.2KJ\;m^{-2}\;day^{-1}$ of UV-B radiation, and those in the $3.2KJ\;m^{-2}\;day^{-1}$ and water stress were similar. UV-B radiation and water stress reduced both water content in the seedlings and leaf water potential, and increased leaf osmatic pressure. The water content of leaves and shoots was reduced more rapidly by UV-B radiation than by water stress treatment. In conclusion, growth responses and physiological changes in water relation by supplemental UV-B radiation which was applied to the hardening phase of container-grown Betula platyphylla seedlings were similar results to the water stress treatment.

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Assessment of Appetite and Nutritional Status in Cancer Patients Undergoing Radiation Therapy : A Prospective Study (방사선치료를 받은 암환자의 식욕상태 및 영양상태 변화양상 평가)

  • 소향숙
    • Journal of Korean Academy of Nursing
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    • v.29 no.6
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    • pp.1179-1191
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    • 1999
  • This study was conducted to identify appetite and nutritional status of 48 cancer patients who have been irradiated over 150$\textrm{cm}^2$ on chest or pelvic area over the three-month period. The data were gathered 3 phases, Each from initiation to completion of radiotherapy through the questionnaires of anorexia, the anthropometric and biochemical measures were used such as weight, TSF, MAC, MAMC, serum albumin and hemoglobin, TLC. Using SAS program, data were analyzed by percentage, Mean$\pm$SD, and two-way repeated measures ANOVA. The results were summarized as follows : 1. Eighty five percent(85%) of the subjects were aged from fifties to sixties. Cancers in the chest area occurred in 100% of men, 56% of the all subjects. The other 44% were pelvic cancer and 71% of the pelvic cancer occurred in women. 2. There were no significant differences in the appetite scores by all groups(characteristics). Changes of the appetite score over time were statistically significant by age, sex, cancer areas staging, treatment modality, and radiation dosage (F=4.0, p=.022; t=6.09, p=.003; t=4.90, p=.009; F=3.28, p=.042; t=5.04, p=.0084; t=4.76, p=.011). The appetite score on the 2nd phase (4 weeks after initiating radiotherapy) decreased from the 1st phase (initiating irradiation), and then increased on the 3rd phase (completing irradiation). 3. There were no significant differences in the body weight and MAMC by all characteristics, and no changes in the body weight and MAMC over time. However there were significant differences of TSF, MAC, level of hemoglobin, level of albumin, and TLC by all characteristics during the three phases. TSF of the men and the chest cancer were lower than those of the women and the pelvic cancer (t=73.20, p=.0001; t=22.91, p=.0001). And there was significant difference by cancer staging(F=3.19, p=.050). But there was no change in TSF over time. MAC of the men and the chest cancer were lower than those of the women and the pelvic cancer each(t=9.23, p=.004; t=17.85, p=.0001). But no change in MAC over time. Levels of hemoglobin had significant differences by age, sex and cancer areas; levels of hemoglobin of older than the fifties, men, and chest area were higher than those on the others(F=3.82, p=.029; t=21.75, p=.0001; t=8.71, p=.005). Levels of albumin were significant differences by sex and cancer areas; levels of albumin on women, and pelvic area were higher than those on the others(t=6.34, p=.015; t=15.23, p=.0003). While the levels of hemoglobin were changed over time, levels of albumin were not changed and within normal limit. TLC of the men was higher than women(t=5.05, p=.029). Changes in the level of hemoglobin over time were statistically significant according to sex, cancer areas, and radiation dosage(t=3.49, p=.035; t=3.36, p=.039; t=4.04, p=.021).

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Acute Myelogenous Leukemia Developed after Radioactive Iodine Therapy and Palliative Radiation Therapy in Metastatic Papillary Thyroid Cancer (갑상선 유두암환자에서 방사성 옥소 치료와 고식적 방사선 치료 후 발생한 급성 골수성 백혈병)

  • Ko, Tae-Young;Kwag, Jae-Sik;Oh, Kyung-Suk;Lee, Seung-Bai;Chung, Byung-Sun;Kim, Eun-Sil;Kim, Chong-Soon
    • The Korean Journal of Nuclear Medicine
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    • v.32 no.5
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    • pp.436-442
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    • 1998
  • Radioactive iodine treatment has been widely used for nearly 50 years in the treatment of thyroid cancer to ablate residual thyroid tissue after thyroidectomy and to treat metastatic disease. Leukemia is a rare complication associated with the radioactive iodine therapy. The occurrence of leukemia is known to be related to the cumulative dosage of I-131 more than 37 GBq (1 Ci) and also associated with the intervals of less than 12 months between the repeated doses. We report a case of a 52 year-old female patient with papillary cancer of thyroid who developed acute myelogenous leukemia after the total 20.4 GBq (550 mCi) of I-131 therapy over 3.2 years and palliative radiation therapy (3000 cGy) due to multiple bone metastasis of papillary cancer.

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The mRNA Expression of Radio-Sensitive Genes Exposed to Various Dosage of Ionizing Radiation in U-937 Cell (U-937 세포에서 이온화 방사선의 조사선량에 따른 감수성 유전자들의 발현 변화)

  • 김종수;임희영;오연경;김인규;강경선;윤병수
    • Toxicological Research
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    • v.20 no.1
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    • pp.21-29
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    • 2004
  • We used cDNA microarray to assess gene expression profiles in hematopoetic cell line, U-937, exposed to low doses of ionizing irradiation. The 1,000 DNA elements on this array were PCR-amplified cDNAs selected from named human cancer related genes. According to the strength of irradiation, the levels of some gene expression were increased or decreased as dose-dependent manner. The gene expressions of Tubulin alpha, protein kinase, interferon-alpha, -beta, -omega receptor and ras homolog gene family H were significantly increased. Especially, Tubulin gene was shown 2.5 fold up-regulated manner under stress of 500 rad irradiation than 200 rad. On the other hand, fibroblast growth factor 12 and four and a half LIM domains, etc. were significantly down-regu-lated. Also, tumor protein 53(TP53) related genes that p53 inducible protein, tumor protein 53-binding protein looks of little significance as radiation sensitive manner. The radio-sensitivity of tubulin gene etc. that we proposed could be useful to rapid and correct survey for the bio-damage by exposure to low dose irradiation.

Relative Dose Distribution in the Biological Irradiation Facility at TRIGE Mark-III Reactor

  • Kim, Byung-Sung;Ha, Chung-Woo;Lee, Chang-Kun
    • Nuclear Engineering and Technology
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    • v.7 no.4
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    • pp.277-284
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    • 1975
  • A result of measurement for the relative dose distribution of neutron gamma mixed radiation field in the biological irradiation facility installed at TRIGA Mark-III reactor is described. The relative dose distributions of neutron-gamma mixed radiation field in the biological exposure room have been experimentally determined using a thermoluminescent dosimeter. Presented herein in graphical forms are the experimental results obtained. It as observed that the region commonly having the characteristics of rather homogeneous horizontal and lateral dose distributions is confined to the area bounded by the two planes horizontally parallel to the beam direction with heights of about 40 cm and 130 cm, respectively, at distances beyond 100 cm from the segmentary surface of the aluminum pool liner projected into the the exposure room, while other areas show a steeper gradient in dosage, especially the places adjacent to the segment of the aluminum pool liner and near the inner po${\gamma}$lion of the concrete walls of the exposure room.

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Effect of Diethyldithiocarbamate on Radiation-induced Learning and Memory Impairment in Mouse (방사선 유도 학습기억 장애에 대한 diethyldithiocarbamate의 효과)

  • Jang, Jong-Sik;Kim, Jong-Choon;Moon, Chang-Jong;Jung, U-Hee;Jo, Sung-Kee;Kim, Sung-Ho
    • Journal of Radiation Protection and Research
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    • v.37 no.3
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    • pp.123-128
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    • 2012
  • Evidence suggests that even low-dose irradiation can lead to progressive cognitive decline and memory deficits, which implicates, in part, hippocampal dysfunction in both humans and experimental animals. This study examined whether diethyldithiocarbamate (DDC) could attenuate memory impairment, using passive avoidance and object recognition test, and suppression of hippocampal neurogenesis, using the TUNEL assay and immunohistochemical detection with markers of neurogenesis (Kiel 67 (Ki-67) and doublecortin (DCX)) in adult mice treated with gamma radiation (0.5 or 2 Gy). DDC was administered intraperitonially at a dosage of 1,000 $mg{\cdot}kg^{-1}$ of body weight at 30 min. before irradiation. In passive avoidance and object recognition memory test, the mice, trained for 1 day after acute irradiation (2 Gy) showed significant memory deficits compared with the sham controls. The number of TUNEL-positive apoptotic nuclei in the dentate gyrus (DG) was increased 12 h after irradiation. In addition, the number of Ki-67- and DCX-positive cells were significantly decreased. DDC treatment prior to irradiation attenuated the memory defect, and blocked the apoptotic death. DDC may attenuate memory defect in a relatively low-dose exposure of radiation in adult mice, possibly by inhibiting a detrimental effect of irradiation on hippocampal neurogenesis.

Guideline of Improvement and Evaluation of Prescribing Errors in Colorectal Chemotherapy (대장암 항암 화학요법의 처방 오류 평가 및 개선안 제시)

  • Lim, Hyun-Soo;Lim, Sung Cil
    • Korean Journal of Clinical Pharmacy
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    • v.23 no.2
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    • pp.158-166
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    • 2013
  • Background: Colorectal cancer shows a significant increase in South Korea due to westernization of diet, lack of dietary fiber, drinking and smoking, irregular defecation. There are surgery, chemotherapy, radiation therapy in treatment of colorectal cancer. There may be a medication errors in the process of chemotherapy because of its high toxicity, narrow therapeutic index and the health status of cancer patients. Consequently medication errors can cause increasing the risk of death, prolonging hospital stay and increasing the cost. Among medication errors on medication use process, prescribing errors are of particular concern due to higher risk of serious consequences. It is important for pharmacist to prevent the prescribing errors before reaching patient. Therefore we analyzed the prescriptions of colorectal cancer, classified prescribing errors, suggested guideline to reduce prescribing errors and verified the importance of pharmacist's role in prevention of medication errors activity. Methods: We collected the numbers of prescriptions of colorectal cancer(n=2,373) through anti cancer management program and EMR and analyzed the errors of prescriptions by categories from Oct 1st 2011 to Sep 30th 2012 at Chungbuk National University Hospital. We reviewed the prescriptions as follows - patients' characteristics, the result of test, previous prescriptions, characteristics of antineoplastic agents and patients' allergy, drug sensitivity, adverse events. Prescriptions are classified into inpatient and outpatient and analyzed the errors of prescriptions by categories (dosage form, dose, input, diluents, regimen, product). Results: Total prescription number of inpatient and outpatient of colorectal cancer was 1,193 and 1,180 and that of errors was 107(9%) and 22(1.9%), respectively. In case of errors of categories, the number of errors of dosage form is 69 and 8, errors of dose is 15 and 5, errors of input is 9 and 9 in inpatient and outpatient prescriptions, respectively. Errors of diluents is 8, errors of regimen is 3, errors of product is 3 in only inpatient prescriptions. In case of errors of categories by inpatient department, the number of errors of dosage form is 34 and 35, errors of dose is 7 and 8, errors of input is 6 and 3, errors of diluents is 4 and 4, errors of regimen is 2 and 1, errors of product is 2 and 1 in SG and HO, respectively. In case of outpatient department, the number of errors of dosage form is 8 in HO, errors of dose is 5 in HO, errors of input is 5 and 4 in SG and HO, respectively. Conclusions: The rate of errors of inpatient is higher than that of outpatient. Junior doctors are engaged in prescriptions of inpatient and pharmacist need to pay attention to review all prescriptions. If prescribing errors are discovered, pharmacist should contact the prescriber and correct the errors without delay. The guideline to reduce prescribing errors might be upgrading software of anti cancer management program, education for physicians as well as pharmacists and calling prescriber's attention to preventing recurrence of errors.