• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 2005.10a
• /
• pp.150-152
• /
• 2005

환경친화적 기술로 알려진 방사선조사기술(RT: Radiation Technology)을 이용하여 돈피 유래 올리고펩타이드를 제조하고자 하였다. 생 박 돈피를 hammer mill과 chopper를 이용하여 조분쇄한 후 $-20^{\circ}C$ 아세톤으로 탈지하였고, ${\gamma}$-ray irradiator를 이용하여 0, 20, 40, 60, 100, 150, 200, 250, 300 kGy의 총 흡수량을 얻도록 탈지돈피에 방사선조사를 실시하였다. 방사선조사에 의한 탈지돈피의 pH 변화는 0${\sim}$100 kGy 조사선량에서는 미비했으나, 150 kGy 이상에서는 소폭 증가하였다. 탈지돈피의 단백질 함량 중 콜라겐 함량은 93% 이었으며 방사선조사된 돈피콜라겐을 효소처리하면 효소반응 시간이 길어질수록 약 24 kDa 범위에서 밴드가 확인되었고, 100 kGy 이상의 고선량에서는 효소반응 2시간 이후 10% polyacrylamide 전기영동 겔의 최 하단에 머무는 분자량의 펩타이드가 다량 관찰되었다. 용해도 변화는 20${\sim}$60 kGy의 선량에서는 효소반응 시간이 길어질수록(1시간${\sim}$4시간) 최대 65${\sim}$80%의 용해도 증가를 보였고, 반면에 100 kGy 이상에서는 효소반응 시간에 관계없이 80% 이상, 300 kGy에서는 90% 이상의 용해도를 보여주려다. 점도와 탁도는 100 kGy 이상의 고선량에서 짧은 효소반응 시간(1시간)에 급격히 감소하였다. 가수 분해물(300 kGy)을 gel permeation chromatography한 결과 분자량 9,000 Da의 주 피크가 검출되었다.

• Korean Journal of Food Science and Technology
• /
• v.33 no.3
• /
• pp.338-344
• /
• 2001

The effect of gamma-irradiation on the microbiological and general qualities of Kanjang (fermented soy sauce, Korean type) and Shoyu (fermented soy sauce, Japanese type) was studied. Samples were prepared, irradiated at 5, 10 and 20 kGy, and then stored at $25^{\circ}C$ for 18 weeks. The results showed that the Bacillus spp. was inactivated by 3 log cycles with the irradiation dose of 10 kGy and the number of Bacillus cells that survived from 10 to 20 kGy of gamma irradiation was decreased gradually during storage. Yeasts and Lactobacillus were nearly eliminated at 5 to 10 kGy of irradiation. The $D_{10}$ values of Bacillus, yeast and Lactobacillus in Shoyu were 2.67 kGy, 0.81 kGy and 1.30 kGy, in Kanjang were 2.75 kGy, 0.99 kGy and 1.47 kGy, respectively. The general quality of gamma irradiated Shoyu and Kanjang, such as total nitrogen, amino nitrogen, protease activity and pH were more stable than that of control during storage periods. Decolorization was observed just after irradiation, but the color was recovered during storage. The sensory evaluations showed that irradiated samples were more acceptable. Therefore, it was considered that gamma irradiation was effective for maintaining better quality of Shoyu and Kanjang during storage.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.27 no.1
• /
• pp.107-122
• /
• 1997

Radiation sensitivity data was generated for two human cancer cell lines(KB, RPMI 2650) and human primary gingival fibroblast was tested three times using a viable cell number counting with a hemocytometer, MTT(3-[4,5-Dimethylthiazol2-yl]-2,5-diphenyl tetrazolium bromide) assay, and LDH(Lactate dehydrogenase) assay. Single irradiation of 2, 4, 6, 10, 15, 20Gy were applied to the tumor cell lines and the primary cultured gingival fibroblast The two fractions of 4Gy and 10Gy were seperated with a 4 hour time interval. The irradiation was done with 241.5cGy/min dose rate using /sup 137/Cs MK cell irradiator at room temperature. The obtained results were as followed : 1. There was significantly different viable cell numbers as the amount of radiation dose on the tested cells were cell number counted with a hemocytometer. In fractions, there were more viable cells remaining. 2. Phase-contrast microscopically, radiation-induced morphologic changes were pronounced on the tumor cells, however, almost no differences on the gingival fibroblast. 3. There was significantly different absorbance at 2Gy on RPMI 2600, 4Gy on KB and GF in MTT assay. In fractions, the absorbance was significantly higher on KB. 4. The level of extracellular LDH activity in the experimental group was significantly higher in the 2-4Gy than the control group. 5. The total level of extracellular and intracellular LDH activity was decreased as increased amounts of radiation dose was applied.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.2
• /
• pp.625-629
• /
• 2011

A quantitative analysis of the decreasing rate of the monomer and increasing rate of the polymerization was made by monitoring radiation level increments using Raman spectroscopy within the therapeutic radiation range for a normoxic polymethacrylic acid gel dosimeter. The gel dosimeter was synthesized by stirring materials such as gelatin, distilled water, methacrylic acid, hydroquinone and tetrakis phosphonium chloride at $50^{\circ}C$, and the synthesized gel was contained in a 10- mm diameter and 32-mm high vial to conduct measurement. 24 hours after gel synthesis, it was irradiated from 0 Gy to 20 Gy by 2 Gy using a Co-60 radiotherapy unit. With use of the Cryo FE-SEM, structural changes in the 0 Gy and 10 Gy gel dosimeters were investigated. The Raman spectra were acquired using 532-nm laser as the excitation source. In accordance with fitting the changes in C-COOH stretching (801 $cm^{-1}$), C=C stretching (1639 $cm^{-1}$) and vinyl $CH_2$ stretching (3114 $cm^{-1}$) vibrational modes for monomer and $CH_2$ bending vibrational mode (1451 $cm^{-1}$) for polymer, sensitive parameter S for each mode was calculated. The values of S for monomer bands and polymer band were ranged in $6.0{\pm}2.6$ Gy and $7.2{\pm}2.3$ Gy, respectively, which shows a relatively good conformity of the decreasing rate of monomer and the increasing rate of polymerization within the range of error.

• Horticultural Science & Technology
• /
• v.19 no.4
• /
• pp.515-520
• /
• 2001

To observe the stimulating effect of low dose ${\gamma}$ radiation on the dormancy breaking and growth, microtubers of two potato cultivars (Solanum tuberosum L. cv. Dejima and cv. Superior) were irradiated at the dose of 0.5-30 Gy. Though it varied with cultivars and storage duration, sprouting rate, plant growth and tuber yield were promoted by 2-8 Gy irradiation in microtuber of 'Dejima' stored at low temperature. On the other hand, in microtuber of 'Superior', sprouting rate was promoted by 2 and 4 Gy irradiation, and the growth and tuber yield by 4 Gy irradiation. These results suggest that low dose of ${\gamma}$ radiation could have stimulating effects on the dormancy breaking of microtuber and potato growth.

• Korean Journal of Food Science and Technology
• /
• v.23 no.4
• /
• pp.410-413
• /
• 1991

Prefried chicken patties were irradiated at dose levels of 0, 2, and 4 kGy using $Co^{60}$ source and stored at $3{\pm}1^{\circ}C$ and $-10{\pm}1^{\circ}C$, separately for the evaluation of color and sensory characteristics. Irradiation dose of 4 kGy slightly darkened the internal color of chicken patties. Except for the internal portion of the frozen samples, an increase (p<0.05) in Hunter 'L' values was observed for both the surface and interior of patties during storage. Upon refrigerated storage, Hunter 'a' values, both on the surface and internally, decreased as the storage period progressed. Only storage period affected (p<0.05) the Hunter 'b' values of patty surfaces and interiors. No difference (p<0.05) in odor, taste, color, and texture of the patties was observed for irradiation dose and storage period as evaluated by triangle tests except between 2 kGy and 4 kGy irradiated samples before forzen storage.

• Journal of Food Hygiene and Safety
• /
• v.15 no.3
• /
• pp.256-261
• /
• 2000

Effect of gamma irradiation on quality properties of half·cooked noodle was studied. The noodle were treated with lactic acid(0.1%, w/w), heat(10 min in boiling water) or their combination after cooking for 3 min, and irradiated at 0, 5 and 10 kGy. The noodle were stored at 25。C for 5 weeks and microbial population, Aw, pH, and texture profiles were examined. Fungi were completely eliminated by gamma-irradiation with 5 or 10 kGy does. Number of aerobic bacteria were also decreased by 2 and 4 log cycles with dose of 5 and 10 kGy, respectively. The D10 values of aerobic bacteria were 2.34∼2.95 kGy. Growth of the aerobic bacteria that survived even at 10 kGy of irradiation were significantly inhibited during storage. Acidification of half-cooked noodle was suppressed by gamma irradiation but A${_w}$ were not affected. Stickiness was decreased at the beginning of storage by gamma irradiation but was restored after 3 weeks. The results indicated that the gamma irradiation would be useful to improve quality and storage stability of half-cooked noodle.

• Korean Journal of Food Science and Technology
• /
• v.30 no.3
• /
• pp.517-522
• /
• 1998

Hydrocarbons in soybeans were analyzed to determine whether the hydrocarbons can be applied for detecting post-irradiation of soybeans. Yellow and green soybeans were irradiated at 0.5, 1, 3, and 6 kGy. Fats were extracted with hexane and then hydrocarbons were separated from the fat through Florisil column. The hydrocarbons were analyzed with GC. Hydrocarbons 17:2, 16:3, 17:1, and 16:2 were detected in the samples irradiated at 0.5 kGy or higher, but not in the unirradiated ones. The detection levels of hydrocarbons increased with the dose of the irradiation. When unirradiated or irradiated soybeans were roasted or boiled, these hydrocarbons were detected in the samples irradiated at 1 kGy or higher, but not in the unirradiated ones. A blind test confirmed that the hydrocarbon determining method could detect the soybeans irradiated at 1 kGy.

• Journal of Magnetics
• /
• v.22 no.1
• /
• pp.141-145
• /
• 2017

This paper uses a glass dosimeter to evaluate the lens-absorbed dose of scattered radiation generated in tomotherapy intensity modulated radiation therapy (IMRT). The head and neck portion of the rando phantom was subjected to a CT scan. The tomotherapy plan was designed to ensure delivery of the prescribed total 70 Gy day 2.2 Gy. With the lens portion of the glass dosimeter, a 5mm bolus was subjected to the scattered radiation treatment, and the dose was measured in each of the three megavoltage CT (MVCT) modes. The result is multiplied by 30 times and was determined once as the mean value. The measurement at the MVCT Coarse mode is RT mode 10.797 mGy, that for the Normal mode is 13.360 mGy, for the Fine mode is a maximum of 22.872 mGy, and for the treatment mode is 895.830 mGy. A small amount of scattered radiation in the MVCT is measured in the lens scattered radiation, but scattered radiation during treatment was measured to be near 1 Gy on the lens. Compared to a one-time radiation treatment of 2.2 Gy, the survey showed something unexpected in that it was half the value of that research to the patient. Therefore, will be aware of how much of an influence there will be on sensitive organs, such as the lens by scattered radiation generated during intensity modulated radiation therapy.

• Clinical and Experimental Reproductive Medicine
• /
• v.47 no.4
• /
• pp.284-292
• /
• 2020

Objective: This study investigated whether adding outer-well medium to inhibit osmotic changes in culture media in a dry-type incubator improved the clinical outcomes of in vitro fertilization-embryo transfer (IVF-ET) cycles. Methods: In culture dishes, the osmotic changes in media (20 µL)-covered oil with or without outer-well medium (humid or dry culture conditions, respectively) were compared after 3 days of incubation in a dry-type incubator. One-step (Origio) and G1/G2 (Vitrolife) media were used. Results: The osmotic changes in the dry culture condition (308 mOsm) were higher than in the humid culture conditions (285-290 mOsm) after 3 days of incubation. In day 3 IVF-ET cycles, although the pregnancy rate did not significantly differ between the dry (46.2%) and humid culture (51.0%) groups, the rates of abortion and ongoing pregnancy were significantly better in the humid culture group (1.5% and 49.5%, respectively) than in the dry culture group (8.3% and 37.8%, respectively, p<0.05). In day 5 IVF-ET cycles, the abortion rate was significantly lower in the humid culture group (2.2%) than in the dry culture group (25.0%, p<0.01), but no statistically significant difference was observed in the rates of clinical and ongoing pregnancy between the dry (50.0% and 25.0%, respectively) and humid culture groups (59.5% and 57.3%, respectively) because of the small number of cycles. Conclusion: Hyperosmotic changes in media occurred in a dry-type incubator by evaporation, although the medium was covered with oil. These osmotic changes were efficiently inhibited by supplementation of outer-well medium, which resulted in improved pregnancy outcomes.