• Korean Journal of Environmental Agriculture
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• v.18 no.1
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• pp.41-47
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• 1999

To investigate the combined effect of gamma ray irradiation and NaCl treatment on Tradescantia somatic cell pink mutations, potted plants of Tradescantia 4430 were evenly sprayed with NaCl solution(170mM) 24 hours before irradiation(NaCl+${\gamma}$) and after irradiation(${\gamma}$+NaCl). Irradiation doses were 0.3, 0.5, 1.0 and 2.0 Gy of gamma-ray. The plants irradiated only with gamma radiation were used as control group(CT). Frequency of pink mutation increased linearly with irradiation close and the peak interval of elevated mutation frequencies appeared during 6∼12 days aver irradiation in all the experimental groups. The slope of dose-response curve in CT was 5.99($r^2$=0.99), while it were 4.55($r^2$=0.98) in NaCl+${\gamma}$ and 4.33($r^2$=0.99) in ${\gamma}$+NaCl. It seemed that pre- and post-treatment of NaCl had a protective effect it against radiation-induced cell damages since it decreased the slope value by more than 24%. It is suggested that protective effect on DNA damages can be invoked in irradiated stamen hair cells by NaCl treatment.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.415-422
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• 2013

This study was conducted to establish the optimum LED light source and quality for growth of Wasabia japonica seedlings in the LED chamber plant factory system. The light treatments were combined with four colors LED (red, blue, white, far-red), irradiation time ratio of the red and blue LED per minute(1:1, 2:1, 5:1, 10:1), and duty ratio of mixed light (100%, 99%, 97%). The growth response of W. japonica was the greatest in the R + B mixed light treatment, and seedlings grown in the red LED alone was higher than blue LED alone in the monochromic radiation treatments. In the R + B mixed LED, 1:1 ratio of R and B was the best for total biomass and tiller production. In mixed light treatments, the growth response of W. japonica was highest in the 100% duty ratio with R + B mixed light, while that was highest in the 97% duty ratio with R + B + W mixed light. Leaf area and dry weight were increased in the red light treatment alone, while specific leaf area was increased in the blue light alone. With the increasing red LED light ratio, leaf area and dry weight of W. japonica was significantly increased under the R + B mixed light treatment. In mixed light treatments, the leaf growth responses of W. japonica was highest in the 97% duty ratio with R+B mixed light, while that was highest in the 100% duty ratio with R + B + W mixed light. For cultivating W. japonica in a plant factory, treating red LED supplemented with a blue light or higher ratio of the red to blue LED was benefit to promote the growth of W. japonica.

• The Korean Journal of Food And Nutrition
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• v.23 no.1
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• pp.30-38
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• 2010

This study was conducted to determine the effects of vitamin C on the activity of liver function enzymes and electromicrographic changes in white rats treated with aflatoxin $B_1(AFB_1)$ or X-ray and $AFB_1$. Six week-old male Sprague-Dawley rats were randomly divided into five groups: a control group, $AFB_1$ treated group, $AFB_1$ treated group with vitamin C, X-ray and $AFB_1$ co-treated group, X-ray and $AFB_1$ co-treated group with vitamin C. On the first day of the experiment, only one dose of X-rays was exposed to the entire liver at 1,500 cGy. Next, vitamin C was injected at 10 mg/kg body weight by intraperitoneal injection, followed 1 hr later by the administration of 0.4 mg/kg of $AFB_1$ by intraperitoneal injection. These treatments were then administered every three days over a period of 15 days. On the 16th day of treatments, the animals were sacrificed. Analysis of the activity of the liver function enzymes, GOT, ALK phatase and LDH, in the sera of rats revealed that they were somewhat increased by $AFB_1$ treatment, X-ray and $AFB_1$ co-treatment when compared to the control group. Furthermore, the activity of these enzymes decreased in response to administration of vitamin C. Especially, the levels of GOT were remarkably decreased in the $AFB_1$ treated group treated with vitamin C when compared to the group treated with $AFB_1$ alone(p<0.001). Electromicrographic analysis revealed cloudy swelling, necrosis, vesicular degeneration and fat accumulation of hepatocytes in response to treatment with $AFB_1$ or co-treatment with X-ray and $AFB_1$. However, the destruction of hepatic cells was considerably lower in the vitamin C-treated group. These results indicate that vitamin C had ameliorating effects on the hepatic cell damage.

• Clinical and Experimental Pediatrics
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• v.48 no.2
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• pp.186-190
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• 2005

Purpose : The purpose of this study was to evaluate the responses and toxicities of risk-adapted chemotherapy in pediatric intracranial germ cell tumors(IC-GCT). Methods : Fourteen patients who were diagnosed as IC-GCT from October 2002 to December 2003 received chemotherapy as an initial treatment modality. The low risk(LR) group was defined as follows : Pure germinoma and normal AFP level. Beta-hCG level 50 mIU/mL or less. The others belonged to the high risk(HR) group. Chemotherapy was composed of cisplatin, cyclophosphamide, etoposide and vincristine. Double doses of cisplatin and cyclophosphamide was used in HR patients. Results : Pathologic confirmation was done in all but one. Median age at diagnosis was 11.6 yr (1.2-18.7 yr), and nine patients belonged to the HR group. Tumor markers were normalized after chemotherapy in all patients whose tumor markers had been elevated. Four LR patients(80 percent) and seven HR patients(77.8 percent) showed complete response(CR) at the end of chemotherapy. An additional two of the three patients with partial response(PR) achieved CR after radiation therapy (RT), and the remaining one relapsed before RT. Four LR and all HR patients experienced infectious episodes that required hospitalization. Four of the nine HR patients(44.4 percent) suffered from tinnitus, three of whom developed sensorineural hearing loss. All but one are surviving, event-free, with a median follow-up of 13.9 mo(8.1-22.3 mo). Conclusion : Risk-adapted cisplatin-based chemotherapy was effective even in HR patients, but regimen modification seems to be necessary to avoid an unacceptably high toxicity rate.

• Radiation Oncology Journal
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• v.20 no.2
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• pp.108-115
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• 2002

Purpose : A retrospective study was undertaken to determine the role of conventional radiotherapy with or without surgery for treating a supraglottic carcinoma in terms of the local control and survival. Materials and Methods : From Jan. 1986 to Oct. 1996, a total of 134 patients were treated for a supraglottic carcinoma by radiotherapy with or without surgery. Of them, 117 patients who had completed the radiotherapy formed the base of this study. The patients were redistributed according to the revised AJCC staging system (1997). The number of patients of stage I, II, III, IVA, IVB were $6\;(5\%),\;16\;(14\%),\;53\;(45\%),\;32\;(27\%),\;10\;(9\%)$, respectively. Eighty patients were treated by radical radiotherapy in the range of $61.2\~79.2\;Gy$ (mean : 69.2 Gy) to the primary tumor and $45.0\~93.6\;Gy$ (mean : 54.0 Gy) to regional lymphatics. All patients with stage I and IVB were treated by radiotherapy alone. Thirty-seven patients underwent surgery plus postoperative radiotherapy in the range of $45.0\~68.4\;Gy$ (mean : 56.1 Gy) to the primary tumor bed and $45.0\~59.4\;Gy$ (mean : 47.2 Gy) to the regional lymphatics. Of them, 33 patients received a total laryngectomy (${\pm}lymph$ node dissection), three had a supraglottic horizontal laryngectomy (${\pm}lymph$ node dissection), and one had a primary excision alone. Results : The 5-year survival rate (5YSR) of all patients was $43\%$. The 5YSRs of the patients with stage I+II, III+IV were $49.9\%,\;41.2\%$, respectively (p=0.27). However, the disease-specific survival rate of the patients with stage I (n=6) was $100\%$. The 5YSRs of patients who underwent surgery plus radiotherapy (S+RT) vs radiotherapy alone (RT) in stage II, III, IVA were $100\%\;vs\;43\%$ (p=0.17), $62\%\;vs\;52\%$ (p=0.32), $58\%\;vs\;6\%$ (p<0.001), respectively. The 5-year actuarial locoregional control rate (5YLCR) of all the patients was $57\%$. The 5YLCR of the patients with stage I, II, III, IVA, IVB was $100\%,\;74\%,\;60\%,\;44\%,\;30\%$, respectively (p=0.008). The 5YLCR of the patients with S+RT vs RT in stage II, III, IVA was $100\%\;vs\;68\%$ (p=0.29), $67\%\;vs\;55\%$ (p=0.23), $81\%\;vs\;20\%$ (p<0.001), respectively. In the radiotherapy alone group, the 5YLCR of the patients with a complete, partial, and minimal response were $76\%,\;20\%,\;0\%$, respectively (p<0.001). In all patients, multivariate analysis showed that the N-stage, surgery or not, and age were significant factors affecting the survival rate and that the N-stage, surgery or not, and the ECOG performance index were significant factors affecting the locoregional control. In the radiotherapy alone group, multivariate analysis showed that the radiation response and N-stage were significant factors affecting the overall survival rate as well as locoregional control. Conclusion : In early stage supraglottic carcinoma, conventional radiotherapy alone is an equally effective modality compared to surgery plus radiotherapy and could preserve the laryngeal function. However, in the advanced stages, radiotherapy combined with concurrent chemotherapy for laryngeal preservation or surgery should be considered. In bulky neck disease, all the possible planned neck dissections after induction chemotherapy or before radiotherapy should be attempted.

• Journal of Ocean Engineering and Technology
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• v.30 no.2
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• pp.84-90
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• 2016

In this study, a six degree-of-freedom motion analysis of a wind-wave hybrid platform equipped with numerous wave energy converters (WECs) was carried out. To examine the effect of the WECs on the platform, an analysis of one-way coupling was carried out, which only considered the power take-off (PTO) damping of the static WECs on the platform. The equation of motion of a floating platform with mooring lines in the time domain was established, and the responses of the one-way coupled platform were then compared with the case of a platform without any coupling effects from the WECs. The hydrodynamic coefficients and wave exciting forces were obtained from the 3D diffraction/radiation pre-processor code WAMIT based on the boundary element method. Then, an analysis of the dynamic responses of the floating platform with or without the WEC effect in the time domain was carried out. All of the dynamics of a floating platform with multiple wind turbines were obtained by coupling FAST and CHARM3D in the time domain, which was further extended to include additional coupled dynamics for multiple turbines. The analysis showed that the PTO damping effect on platform motions was negligible, but coupled effects between multiple WECs and the platform may differentiate the heave, roll, and pitch platform motions from the one without any effects induced by WECs.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.2
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• pp.387-398
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• 2002

The impact response and damage of CLAS panel was investigated experimentally. The facesheet material used was RO4003 woven-glass hydrocarbon/ceramic and the core material was Nomex honeycomb with a cell size of 3.2mm and a density of 96 kg/㎥. The shield plane used was RO4003 and 2024-T3 aluminum. Static indentation and impact test was conducted to characterize the type and extent of the damage observed in two CLAS panels, and the performance of antenna used in a wireless LAN system. Correlation of peak contact force, residual indentation and the delamination area shows impact damage of the panel with an aluminum shield plane is larger than that of the panel with RO4003 shield plane, although the former is more penetration resistant. The damage was observed by naked eye, ultrasonic inspection and cross sectioning. The shape and size of delamination was estimated by ultrasonic inspection, and the area of delamination linearly increases as impact energy increases. The performance of impact damaged antenna was estimated by measuring return loss and radiation pattern. It was revealed that the performance of antenna was related to the impact damage and there was a threshold that the performance of antenna fell as impact energy level changed. The threshold was between the impact energies of 1.5J and 1.75J.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6433-6438
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• 2013

In hepatocellular cancer (HCC), lack of response to chemotherapy and radiation treatment can be caused by a loss of epigenetic modifications of cancer cells. Methionine adenosyltransferase 1A is inactivated in HCC and may be stimulated by an epigenetic change involving promoter hypermethylation. Therefore, drugs releasing epigenetic repression have been proposed to reverse this process. We studied the effect of the demethylating reagent 5-aza-2'-deoxycitidine (5-Aza-CdR) on MAT1A gene expression, DNA methylation and S-adenosylmethionine (SAMe) production in the HCC cell line Huh7. We found that MAT1A mRNA and protein expression were activated in Huh7 cells with the treatment of 5-Aza-CdR; the status of promoter hypermethylation was reversed. At the same time, MAT2A mRNA and protein expression was significantly reduced in Huh7 cells treated with 5-Aza-CdR, while SAMe production was significantly induced. However, 5-Aza-CdR showed no effects on MAT2A methylation. Furthermore, 5-Aza-CdR inhibited the growth of Huh7 cells and induced apoptosis and through down-regulation of Bcl-2, up-regulation of Bax and caspase-3. Our observations suggest that 5-Aza-CdR exerts its anti-tumor effects in Huh7 cells through an epigenetic change involving increased expression of the methionine adenosyltransferase 1A gene and induction of S-adenosylmethionine production.

• Journal of the Korean Society of Radiology
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• v.9 no.6
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• pp.363-367
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• 2015

Digital radiography is divided into the direct method using photoconductor and indirect method using phosphor based on the principles in acquiring the image information, but both have different advantages and disadvantages. Therefore, this study conducted a preliminary research on the structure of the hybrid detector that combined phosphor and photoconductor to improve the sensitivity of X-ray. As a result, when the tube voltage was adjusted at 30ms of exposure time, the direct structure displayed an overall excellent sensitivity, but at the exposure time of 50ms or more, the hybrid structure displayed a better outcome. This seems to have enough research value considering that various clinical examinations usually include 50ms or more exposure time.

• Journal of Korean Neurosurgical Society
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• v.46 no.3
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• pp.245-251
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• 2009

Objective : The authors analyzed the effectiveness and therapeutic response of Novalis shaped beam radiosurgery for metastatic brain tumors, and the prognostic factors which influenced the outcome. Methods : We performed a retrospective analysis of 106 patients who underwent 159 treatments for 640 metastatic brain lesions between January 2000 and April 2008. The pathologies of the primary tumor were mainly lung (45.3%), breast (18.2%) and GI tract (13.2%). We classified the patients using Radiation Therapy Oncology Group Recursive Partitioning Analysis (RPA) and then analyzed the survival and prognostic factors according to the Kaplan Meier method and univariate analysis. Results : The overall median actuarial survival rate was 7.3 months from the time of first radiosurgery treatment while 1 and 2 year actuarial survival estimates were 31% and 14.4%, respectively. Median actuarial survival rates for RPA classes I, II, and III were 31.3 months, 7.5 months and 1.7 months, respectively. Patients' life spans, higher Karnofsky performance scores and age correlated closely with RPA classes. However, sex and the number of lesions were not found to be significantly associated with length of survival. Conclusion : This result suggests that Novalis radiosurgery can be a good treatment option for treatment of the patients with brain metastases.