• Korean journal of applied entomology
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• v.60 no.2
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• pp.255-262
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• 2021

The potato tuber moth, Phthorimaea operculella (Zeller) has been known as a quarantine pest of potato. This study investigated inhibition doses of electron beam irradiation (EBM) by comparing their effects on the development and reproduction and DNA damage of the insect pest. Eggs (0-12 h old), larvae (3^rd and 5^th instar), pupae (less than 1 d old after pupation) and adults (less than 1 d old after emergence) were irradiated with increasing doses of EBM. The EBM with 150 Gy could not completely prevent the hatchability of eggs and pupation of the hatched larvae. The hatchability from the irradiated eggs were 19.3%. However, adult emergence from the irradiated eggs were completely inhibited. When 3^rd and 5^th instar larvae were irradiated at 100 Gy, the adult emergence from the irradiated larvae and the fecundity of the adults were completely inhibited. When pupae and adults were irradiated at 300 Gy and 400 Gy, respectively, the hatchability of the F₁ eggs was completely inhibited. The alkaline comet assay on the level of DNA damage by EBM in P. operculella adults indicates that the EBM increased DNA damage level in a dose-dependent manner, and the damage was repaired in a time-dependent manner. These results may recommend EBM of 150 Gy as a phytosanitary treatment for P. operculella. However further confirmative study is required for the practical application of this EBM dose for P. operculella disinfestation.

• Radiation Oncology Journal
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• v.13 no.1
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• pp.1-7
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• 1995

Purpose : To evaluate the efficacy of radiotherapy for the low-grade astrocy-tomas and confirm the variables influencing treatment results. Materials and Methods : Forty-six patients with low-grade astrocytoma received radiotherapy after surgical removal (36 patients) or biopsy (10 patients) from 1979 to 1990. Twenty patients had grade I histology and 26 had grade II. External radiotherapy was done by conventional schedule with the total dose of 45 to 60 Gy (median: 54 Gy). The median follow-up period was 5 years. Results : The 2- and 5-year survival rates were $80\%$ and $72\%$, respectively and the 2- and 5-year progression-free survival was $75\%$ and $63\%$, respectively. The survival was influenced significantly by the histologic grade, the histologic type, and performance status. Major complication was not found. Conclusion: In spite of good survival, the local failure was still the major problem. Age and the extent of surgery as well as three favorable factors should be considered in the future treatments.

• Radiation Oncology Journal
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• v.8 no.2
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• pp.199-205
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• 1990

During a ten-year period from 1978 through 1987, 44 patients with T2NOMO glottic cancer were treated with radical radiation therapy at the Yonsei University Medical Center. Forty-two patients had a minimum follow-up of 3 years, and $81\%$ had at least five years of follow-up. Patients were staged according to the AJCC system. Forty-two patients have been analyzed in detail with respect to two variables: the status of vocal cord mobility and the degree of local extension of the disease. Five-year local recurrence free survival rates were as follows: All 42 patients, $53.3\%$ patients with normal vocal cord mobility (n =18), $69.1\%$ versus patients with impaired vocal cord mobility (n=24), $43.4\%$(p<0.05); patients with subglottic extension (n=15), $36.7$ versus patients without subglottic extension (n=29), $61.9\%$ (p<0.05). The most favorable Prognostic group included the patients with normal mobility without subglottic extension (n=14), $83.1\%$. On the basis of this analysis, we confirmed the presence of heterogeneity in T2NOMO glottic cancer This study indicates that further randomized controlled trials are warranted to evaluate.

• Radiation Oncology Journal
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• v.8 no.2
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• pp.213-218
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• 1990

A retrospective analysis was performed or 102 patients with non-small cell lung cancer who received the curative radiotherapy from August 1985 to October 1988 at the Department of Therapeutic Radiology of Chonnam University Hospital. The follow-up period was ranged from 1 to 37 months and the median follow-up time was 15 months. The acturial 1 and 2 year survival rate of all the patients was $28\%\;and\;5\%$, respectively. The median survival was 10 months for stage II, 6 months for stage IIIA, and 9 for IIIB and the actuarial 2 year survival tate was $12.5\%,\;12.1\%,\;and\;0\%$ respectively. The treatment failure was identified in 32 patients and the locoregional failure was seen in 9 patients ($28\%$) and the distant failure in 23 patients ($72\%$). The initial performance status was related to the survival with statistical significance (p<0.01), but the survival difference by the radiation dose was not statistically significant (p>0.05).

• Journal of Bio-Environment Control
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• v.9 no.4
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• pp.230-236
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• 2000

For extension of storability, onion bulbs produced in Cheju Island were exposed to ${\gamma}$-ray irradiation at a dosage of 0, 3, or 6Krad and stored in a natural cavern, or in low (2$^{\circ}C$) or ambient temperature storage condition. Sprouting began from approximately five months in storage, regardless of storage condition, and increased as the storage period increased. From early August, sprouting as high as 50% occurred in the natural storage cavern, and 20% in ambient temperature storage when bulbs were treated with 0 krad ${\gamma}$-ray. However, bulbs treated with 3 or 6krad ${\gamma}$-ray did not any sprouting until six months in storage. No significant weight loss was observed in all treatments until sprouting occurred from 40 days after the initiation of storage. Weight loss, however, increased remarkably after 40 days in storage, indicating that it was closely related to sprouting during storage. Bulbs stored at 2$^{\circ}C$ showed 5~10% rot, but were still edible. Percent rot reached to as high as 50% in bulbs unirradiated and stored at ambient temperatures after seven months, while it in irradiated bulbs reached to 5, 33, and 30% at 2$^{\circ}C$, in a natural cavern, and ambient temperatures, respectively. Sugar contents slightly increased in irradiated bulbs in the later storage period under ambient temperatures, while sugar contents in irradiated bulbs in the later storage period under ambient temperatures, while sugar contents in Allium vegetables generally decrease in later storage if unirradiated. Sulfur content slightly increased in irradiated bulbs in the early storage period and decreased gradually in all treatments in the later storage stage.

• Radiation Oncology Journal
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• v.5 no.2
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• pp.105-110
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• 1987

Fourty nine patients with squamous cell carcinoma of oral tongue were reviewed retrospectively for the evaluation of clinical manifestation and for the comparison between therapeutic modalites. The gross shape of the tumor was infiltrative in 22, ulcerative in 12, ad ulcer-oinfiltrative type in 10 patients. Direct extension of the tumor was most commonly to the floor of the mouth. The incidence of nodal metastasis generally increased with tumor stage. $55\%$ of the patients showed neck nodal metastasis at the time of diagnosis. Ipsilateral subdigastric node were most commonly involved, followed by submandibular nodes. The 5-year survival rate of patients treated with surgery and radiotherapy was $58.7\%$ in contrast to $21.6\%$ in radiation alone group. Overall 5-year survival rate was $31\%$ In radiation alone group, half of the patients in stage I, II were locally controlled. But the local control In stage III, IV was much inferior to early lesions. Especially, of 4 patients combined with implantation technique, 3 were completely controlled. 5-year survival rate of these implanted patients was $50\%,\;49.4\%$ of patients treated over 7,000cGy survived 5 years. This was significant in contrast to $6.4\%$ of the group treated below 7,000cGy. The most common sites of failures were primary sites. In early lesions primary radiotherapy with implantation would be an appropriate treatment in cancer of oral tongue, operation reserved for radiation failure. Operation and adjuvant radiotherapy is recommended in cases of advanced disease.

• Korean Chemical Engineering Research
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• v.52 no.1
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• pp.113-118
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• 2014

We have investigated the combined pretreatment of electron beam irradiation (EBI) and water steam as a kenaf core pretreatment process. After each sample was exposed to electron beam dose ranging from 50 to 1,000 kGy, the irradiated sample was treated by water steam using an autoclave for 5-h at $120^{\circ}C$. The pretreated samples were characterized using FTIR-ATR and XRD. FTIR spectra and XRD analysis of nonpretreated and pretreated samples confirm that crystallinity changes were observed before and after the pretreatment. The crystallinity index (CrI) was increased from 50.6% for nonpretreated sample 55.0% for 500 kGy exposed sample. And then, we analyzed sugar yield that is the amount of produced mono-saccharides in pretreated sample by enzymatic hydrolysis; an enzyme activity rate was 70 FPU/mL and 40 CBU/mL, and the loading time was 24, 48 and 72-h. The highest sugar yield was 83.9% at 500 kGy after 72-h for enzymatic hydrolysis. The sugar yield of enzymatic hydrolysis for pretreatment samples was increased as doses are subsequently changed to 100, 200 and 300 kGy, allowing to give 50.8%, 58.6% and 67.9%, respectively.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.1
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• pp.50-53
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• 2019

Purpose Yttrium-90 (Y-90) is high-energy beta emitters ($E{\beta}$, max = 2.28 MeV) with the mean penetration depth of 2.5 mm in tissue. Radioactive microspheres containing Y-90 is widely used for the transarterial radioembolization of hepatocellular carcinoma. However, bremsstrahlung radiation from Y-90 can cause the external radiation exposure to medical staff who handle the Y-90 microspheres. In this study, shielding device for Y-90 microspheres was developed to minimize the external radiation exposure. Materials and Methods Y-90 microsphere shielding device was made from 6 mm thicknesses of tungsten including the lead glass window. Radiation shielding ability of Y-90 microsphere shielding device was evaluated using 4 GBq of $SIR-Spheres^{(R)}$ Y-90 microspheres. The bremsstrahlung radiation was measured using radiation survey meter. Results The mean radiation dose of Y-90 microspheres in acrylic shield was $261.7{\pm}2.3{\mu}Sv/h$ (n=5) at 10 cm away from the shield. With the additional tungsten shielding device, it was $23.7{\pm}1.3{\mu}Sv/h$ (n=5). Thus, the bremsstrahlung radiation dose was decreased by 90.9%. At 50 cm away from the shield, bremsstrahlung radiation was reduced by 89.2% after using tungsten shielding device. Conclusion During the preparation and radioembolization of Y-90 microsphere, medical staff are exposed to external radiation. In this study, we demonstrated that the use of tungsten shielding device devices significantly reduced the amount of bremsstrahlung radiation. Y-90 microsphere tungsten shielding device can be highly effective in reducing the bremsstrahlung radiation.

• Journal of radiological science and technology
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• v.37 no.3
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• pp.187-193
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• 2014

The purpose of this study was to analyze the effect on the selectivity on of high-voltage rectification device that measured the performance of the grid, and the contrast improvement ability (K factor) by measuring the scattered radiation content of the transmitted X-rays. The scattered radiation generated when the X-ray flux comes from the diagnostic X-ray generator that passes through an object. Targeting four different rectifications of X-ray generators, the mean value of the tube voltage and the tube current was measured in order to maximize the accuracy of the generating power dose within the same exposure condition. Using fluorescence meter, the content of the scattered rays that are transmitted through the acrylic was measured depending on the grid usage. When grid is not used, the content of the scattered rays was the lowest (34.158%) with the single-phase rectifier, was increased with the inverter rectifier (37.043%) and the three-phase 24-peak rectification method (37.447%). The difference of the scattered radiation content of each device was significant from the lowest 0.404% to the highest 3.289% while using 8:1 grid, the content of the scattered ray was the lowest with the single content of the scattered ray was the lowest with the single-phase rectifier (18.258%), was increased with the rectifier (25.502%) and the 24-peaks rectification (24.217%). Furthermore, there was difference up to content 7.244% to the lowest content 1.285% within three-phase 24-peaks rectification, inverter rectifications, and single-phase rectifier depending on the selectivity of the grid. Drawn from the statistical analysis, there was a similar relationship between the contrast improvement factor and the K factor. As a result, the grid selectivity and the contrast were increased within the single-phase rectifier rather than the constant voltage rectifier.

• Radiation Oncology Journal
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• v.13 no.1
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• pp.69-78
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• 1995

Seventy four patients with soft tissue sarcomas treated by postoperative radiotherapy in the Department of Therapeutic Radiology, Seoul National University Hospital between August 1979 and September 1990 were analyzed. The follow-up Period ranged from 3 to 145 months with a median of 51 months. Liposarcoma and malignant fibrous histiocytoma(MFH) constituted $54\%$ of the cases and the histologic grades of tumors are as follows: grade I, 23 cases; grade II, 17 cases; grade III, 24 cases: unknown grade, 10 cases. The patients were treated by marginal(17 cases), wide(55 cases) or compartmental(2 cases) excision followed by Postoperative radiotherapy. The total radiation doses were 4200-8820 cGy (median 6000 cGy), 180-200 cGy daily. 5 times per week. Of 74 Patients, 35 ultimately failed. The local control was $62.2\%$ at 5 years and cumulative risk of distant metastasis was $22,3\%$ at 5 years. The overall survival and disease free survival were $72.3\%$, and $53.3\%$ at 5 years, respectively. Survival after appearance of metastasis was $15.1\%$ at 3 years. Patients with liposarcoma experienced better local control than those with other histologic type and tumor grade and surgical resection margin significantly correlated with local recurrence, distant metastasis and overall survival on univariate analysis. In conclusion, re-excision is needed for patients with positive surgical resection margin to improve local control and further therapeutic measures using effective chemotherapy should be explored in the hope of improving overall survival.