• Polymer(Korea)
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• v.33 no.6
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• pp.551-554
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• 2009

Poly (vinyl alcohol) (PVA) and carboxymethyl cellulose (CMC) have received increasing attention in biomedical and biochemical applications because of their properties such as being water-soluble and biocompatible. In this study, a PVA/CMC hydrogel applicable to artificial cartilage was prepared by a freezing-thawing technique and a gamma-ray irradiation. The solid concentration of PVA was 7 wt% and the concentration of CMC was 4 wt%. The freezing/thawing process was repeated twice and the dose of gamma-ray irradiated was 30 kGy. Results of gelation before and after gamma-ray irradiation were similar, but the swelling degree decreased and compressive strength increased. The cytotoxicity was investigated with CCK-8 assay.

• Food Science and Preservation
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• v.13 no.1
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• pp.55-60
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• 2006

Two kinds of composite seasoning products (beef broth powder, polk bone extract powder) were used for a detection trial of gamma irradiation treatment up to 10 kGy by analyzing photostimulated luminescence (PSL), electron spin resonance (ESR) and thermoluminescence(TL). PSL results showed that the photon counts of non-irradiated samples were lower than 700, while those of irradiated samples were higher than 5000, which makes it possible to screen irradiated composite seasoning products at 1 kGy or over from the non-irradiated control. ESR signals measured for both irradiated samples were not irradiation-specific, even though they were dose dependent in the signal intensity. Radiation-induced TL glow curves were found in irradiated beef broth powder and furthernmore, TL ratio $(TL_4/TL_2)$ obtained by a re-irradiation step could verify the detection result of TL1 glow curves, showing ratios lower than 0.05 in the non-irradiated sample and higher than 1.00 in irradiated ones.

• Korean Journal of Food Science and Technology
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• v.44 no.6
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• pp.673-679
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• 2012

Ten commercially available red pepper powders were investigated using photostimulated-luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) analyses to confirm their irradiation status. The application of PSL, TL, and ESR analyses was also confirmed by in-house irradiation. In PSL-based screening, all samples gave negative photon counts (<700 PCs). The PSL calibration dose (1 kGy) showed a low sensitivity of 4 samples, while the others provided reliable screening results. TL glow curves demonstrated maximum peaks after $250^{\circ}C$ for the 6 samples; however 4 samples gave complex TL glow curves with maximum peaks in the range of $185-260^{\circ}C$ (radiation-specific), which could be the effect of an irradiated component in low concentration as the TL ratios of all samples were <0.1. Radiation-specific ESR features were absent in the all commercial samples. Variable irradiation detection properties were found; where the TL analysis showed the possible presence of an irradiated component in 4 samples requiring further monitoring and investigation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.892-898
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• 2005

The effect of gamma irradiation on volatile components of Korean dried ginger (Zingiber officinale Roscoe) was studied and compared with non-irradiated sample. Volatile compounds from non- and irradiated samples were extracted using simultaneous distillation-extraction (SDE) apparatus and analyzed by gas chromatography-mass spectrometer (GC/MS). A total of 83 and 71 compounds were identified and quantified from non-and irradiated dried ginger at dose of 10 kGy. Identified components were hydrocarbons, alcohols, aldehydes, esters, ketones and miscellaneous compounds. The terpenoid compounds in volatile flavor compounds identified from non and irradiatied dried ginger were $98.27\%\;and\;98.12\%$, respectively. $\alpha$ -zingiberene,$\beta$-sesquiphelland reno, geranial, (Z,E) $\alpha$ -farnesene, $\beta$ -phellandene were detected as major volatile compounds of two experimental sample. The amount of volatile components in the samples was changed by irradiation but the profile of volatiles in non- and irradiated dried ginger were the same.

• Radiation Oncology Journal
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• v.4 no.2
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• pp.115-128
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• 1986

Hyperthermia can enhance the radiation effect as a synergistic reaction in combined X-ray irradiation and hyperthermia; hyperthermia sensitize radioresistant S-phase cells and inhibit cellular recovery from sublethal damage. We fabricated 100 watts, 2450 MHz microwave applicator for hyperthermia and planned the method and condition of heating and measured the temperature by using Agar phantom as a preliminary test. For biological examination, 102 rats were divided into 4 groups as hyperthermia, X-ray irradiation (6Gy-15Gy), combined X-ray and hyperthermia, and normal control groups. Microscopic examination of the rectum and bladder was done and the results were as followings: 1. The microwave generator with 100 watts, 2450MHz magnetron could be heating up to $40^{\circ}{\sim}50^{\circ}C$ for one hour in living tissue. 2. The thermal distribution in tissue equivalent phantom with microwave can be maintained at $40^{\circ}{\sim}44^{\circ}C$ in area of 3cm in depth and 2-10cm in diameter. 3. In Hyperthermia alone group, there was submucosal edema of the rectum but no histologic change in the urinary bladder was seen. 4. The minimal necrosis of the mucosa was appeared in the rectum and bladder after 15 days of 6 Gy and 8 Gy irradiation respectively. The minimal necrosis of the muscle layer of rectum and bladder was appeared after 15 days of 8Gy and 60days of 10Gy irradiation respectively. 5. In combined group of radiation and hyperthermia, thermal enhancement ratio (calculated at necrosis of mucosa and muscle layer) of rectum and bladder was 1.0, and it suggest that there is no change of tolerance dose of normal rectum and bladder.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.380-386
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• 2000

Electron beam (EB) was applied to study the sterilizing techniques for powdered red pepper and ginger by determining their quality over gamma radiation (GR) from the microbiological and organoleptic points of view. The samples showed high microbial loads, such as $10^5{\sim}10^6\;CFU/g$ in total aerobic bacteria, negligible levels in yeasts & molds and $10^2\;CFU/g$ in coliforms. EB irradiation at 5 kGy resulted in the reduction of microbial loads by 2 to 3 log cycles, thereby decreasing the levels of total bacteria to $10^2{\sim}10^3\;CFU/g$ and resulting in negative in coliforms. Decimal reduction doses $(D_{10})$ value on the initial bacterial loads in red pepper were $1.50{\sim}1.54\;kGy$ in EB and $1.68{\sim}1.80\;kGy$ in GR, while powdered ginger showed $1.30{\sim}2.27\;kGy$ in EB and $1.45{\sim}2.77\;kGy$ in GR, respectively. EB and GR showed a similar effect on microbial decontamination for both samples. Microbial populations in stored samples for 4 months at room temperature were not remarkably different from the initial loads in all samples. Irradiation caused little changes in Hunter's color parameters, but that were changable during storage. Sensory evaluations on color and odor of powdered samples indicated that no significant differences were observed among the all samples compared. These results revealed that EB irradiation at optimal dose levels for microbial control was not detrimental to the sensory quality of powdered red pepper and ginger.

• Radiation Oncology Journal
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• v.13 no.4
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• pp.339-348
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• 1995

Purpose : Since 1983, authors have conducted a study to evaluate the effect of external radiation therapy and to determine affected factors in management of the patients with malignant obstructive jaundice due to porta hepatis metastasis from stomach cancer. Materials and Methods : Thirty two patients with malignant obstructive jaundice due to porta hepatis metastasis from gastric cancer were presented. We have analysed 23 patients who were treated with external radiation therapy of more than 3000cGy. The radiation dose, disease extent at developement of jaundice, total bilirubin levels before radiation therapy, differentiation of histology, combind treatment, intent of primary surgery, initial stage of gastric cancer were analyzed to determine affected factors in radiation therapy. External radiation therapy was delivered with a daily dose of 180-300cGy, 5 times a week fractionation using 4 MeV linear accelerator. The radiation field included the porta hepatis with tumor mass by the abdominal ultrasonography or CT scan. In twenty three patients received more than 3000cGy, total irradiation dose was ranged from 3000cGy to 5480cGy, median 3770cGy. Among 23 patients, 13 patients were delivered more than equivalant dose of TDF 65(4140cGy/23fx). Results : Among 23 patients, complete, partial and no response were observed in 13, 5, 5 patients, respectively. The median survival for all patients was 5 momths. The significant prolongation of median survival was observed in complete responders(11 months) as compared to partial and no responders(5 months, 5 months respectively) Out of 13 patients with complete response, 6 patients lived more than a year Among 13 patients receiving more than 4140cGy equivalent dose, complete, partial and no response were observed in 10, 2 and 1 patients, respectively. The median survival for all these patients was 9.5 months. The median survival for complete responders(10/13) was 11.5 months. Among 10 patients receiving less than 4140cGy equivalent dose, complete, partial and no response were observed in 3, 3, 4 patients, respetively. The median survival for all these patients was 4.3 months Therefore, the radiation dose affected the results of treatment. For the complete response with prolongation of survival duration, at least 4140cGy equivalant dose should be delivered to porta hepatis. In evaluation of the disease extent, 7 patients of 13 complete responders showed localized disease in porta hepatis or peripancreatic area, but all patients with partial and no response showed wide extensive disease or persistant disease of primary gastric cancer. Therefore. the patients with the localized disease were the higher probability of complete response and long term survival. This study suggested that the radiation dose and the disease extent at developement of jaundice affected in radiation therapy for malignant obstructive jaundice. There were no serious complications related to external radiation therapy. Conclusion : External radiation therapy only could achieve the palliative effect in the patients with malignant obstructive jaundice due to porta hepatis metastasis from stomach cancer. This study suggested that the prolongation of survival duration could be achived in complete responders and radiation dose, extent of disease affected the results of treatment of malignant obstructive jaundice.

• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.27-34
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• 2018

Purpose : To evaluate the effect of carbon couch side rail and vacuum immobilization device in case of lung RPO irradiation. Materials and Methods : The 10, 20, 30 mm thickness of vac-lok's right side were obtained. To measure of doses, glass dosimeters were used and measured reference point is left lung center at the phantom. A, B, C, and D points are left, right, down, and up directions based on the center point. In the state of Side-Rail-Out, place the without vac-lok, with the thickness of 10, 20, and 30 mm vac-lok. After the glass dosimeters was inserted in center, A, B, C, and D points, 100 MU of 6 MV X-ray were irradiated to the referenced center point in the condition of $10{\times}10cm^2$ field size, SAD 100 cm, gantry angle 225, 300 MU/min dose rate. Five measurements were made for each point. In the state of Side-Rail-In, five measurement were made for each point under the same conditions. The average is measured on each of the five Side-Rail-Out and Side-Rail-In measurements. Results : In the presence of side rail, the dose reduction ratio was -11.8 %, -12.3 %, -4.1 %, -12.3 %, -7.3 % for each A, B, C, and D points. In the state of Side-Rail-Out, the dose reduction ratio for the using 10 mm thickness of vac-lok was -0.9 % than without vac-lok. The dose reduction ratio for the using 20 mm thickness of vac-lok was -2.0 %, for the using 30 mm thickness of the vac-lok was -3.0 % than without vac-lok. In the state of Side-Rail-In, the dose reduction ratio for the using 10 mm thickness of vac-lok was -1.0 % than without vac-lok. The dose reduction ratio for the using 20 mm vac-lok was -2.1 %, for the using 30 mm vac-lok was -3.0 % than without vac-lok. Based on the value of no vac-lok dose in the Side-Rail-In state, The dose reduction ratios for the using 10 mm, 20 mm and 30 mm thickness of vac-loks In the Side-Rail-Out that the center point were -12.7 %, -13.7 %, -14.2 % and -12.8 %, -13.8 %, -14.5 % respectively at point A. The dose reduction ratios for the same conditions to the B point were -4.9 %, -6.1 %, -7.1 % and -13.4 %, -14.4 %, -15.5 % respectively at point C. The dose reduction ratios for the same conditions to the D point were -8.4 %, -9.0 %, -10.4 % respectively. Conclusion : The attenuation was caused by presence of side rails and thickness of vac-lok. Pay attention to these attenuation factors, making it a more effective radiation therapy.

• The Journal of Korean Society for Radiation Therapy
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• v.24 no.2
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• pp.183-188
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• 2012

Purpose: The concern of improving the quality of life and reducing side effects related to cancer treatment has been a subject of interest in recent years with advances in cancer treatment techniques and increasing survival time. This study is an analysis of differing scattered dose to the contralateral breast using common different treatment techniques. Materials and Methods: Eclipse 10.0 (Varian, USA) based $30^{\circ}$ EDW (Enhanced dynamic wedge) plan, $15^{\circ}$ wedge plan, $30^{\circ}$ wedge plan, Open beam plan, FiF (field in field) plan were established using CT image of breast phantom which in our hospital. Each treatment plan were designed to exposure 400 cGy using CL-6EX (VARIAN, USA) and we measured scattered dose at 1 cm, 3 cm, 5 cm, 9 cm away from medial side of the phantom at 1 cm depth using ionization chamber (FC 65G, IBA). We carried out measurement by separating effect of medial tangential field and lateral tangential field and analyze. Results: The evaluation of scattered dose to contralateral breast, $30^{\circ}$ EDW plan, $15^{\circ}$ wedge plan, $30^{\circ}$ wedge plan, Open beam plan, FIF plan showed 6.55%, 4.72%, 2.79%, 2.33%, 1.87% about prescription dose of each treatment plan. The result of scattered dose measurement by separating effect of medial tangential field and lateral tangential field results were 4.94%, 3.33%, 1.55%, 1.17%, 0.77% about prescription dose at medial tangential field and 1.61%, 1.40%, 1.24%, 1.16%, 1.10% at lateral tangential field along with measured distance. Conclusion: In our experiment, FiF treatment technique generates minimum of scattered dose to contralateral breast which come from mainly phantom scatter factor. Whereas $30^{\circ}$ wedge plan generates maximum of scattered doses to contralateral breast and 3.3% of them was scattered from gantry head. The description of treatment planning system showed a loss of precision for a relatively low scatter dose region. Scattered dose out of Treatment radiation field is relatively lower than prescription dose but, in decision of radiation therapy, it cannot be ignored that doses to contralateral breast are related with probability of secondary cancer.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.15 no.1
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• pp.1-36
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• 1989

The protective effects of 24 flavonoids against singlet oxygen - induced photohemolysis of rabbit erythrocytes were investigated and compared with their antioxidant activities. 1. All the flavonoid aglycons investigated besides flavone and 7,8-benzoflavone showed tad dose-dependant Protective effects. Especially galagin showed the most Pronounced effect under the experimental condition. 2. The order of the radical-scavenging activities of flavonoids was as follow (-)-EGCG > flavonols > flavonols > flavones > flavanonols. The radical-scavenging activities of flavonoid glycosides were not different from those of their aglycons. 3. When added after irradiation, flavonoids did not alter the photohemolysis pattern of control. In this study, several antioxidant were found and it was newly found that Photohemolysis experiment is a convenient, reproductive diagnostic method in the screening and researching the compound which has antioxidant activity or protective effect on cell membrane against active oxygen species.