• Journal of the Korean Society for Heat Treatment
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• v.35 no.2
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• pp.74-81
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• 2022

This study aims to mitigate the microstructural heterogeneity arising from the manufacture of magnesium alloy plates using the twin roll casting (TRC) process. Homogenization was introduced through hot rolling and heat treatment, followed by confirmation of observed changes in the microstructure. Following the TRC process, the hot rolled 2mm plate exhibited a dendritic cast structure tilted in the roll rotation direction, while central segregation were developed. This nonuniform structure and central segregation disappeared upon heat treatment, followed by recrystallization to form uniform and fine grains. Abnormal grain growth (AGG) was observed over the course of heat treatment; grains exhibiting AGG occupied up to 75% of the total area after having held the sample at 400℃ for 64 h. The formation of coarse grains was also observed during heat treatment at 340℃ over a relatively long duration, though the maximum grain size was significantly smaller than that corresponding to the heat treatment at 400℃. AGG in the 400℃ heat treatment occurred because of movement of the grain boundary, which had been fixed prior as a result of the grain boundary fixing effect of the precipitation phase. The re-dissolution of the Ca₂Mg₅Zn₅ precipitated phase over the long duration of the high-temperature annealing process caused the surrounding grains to disappear and regrow.

• Journal of Applied Biological Chemistry
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• v.57 no.3
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• pp.267-277
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• 2014

Objective of this paper is to assess the available data on the pesticide uses and regulations in the golf courses, and provide the nationwide systematic management options. Numbers of golf courses in Korea are rapidly increasing from 2000s and reached at 421 sites by the end of 2011. Accordingly pesticide usage has been increased with years in direct proportion to the increasing number of golf courses. Amounts of pesticide applied in 2011 were 118,669 kg as of an active ingredient and were in the orders of fungicides (54.9%) > insecticides (24.4%) > herbicides (13.3%) > growth regulators (0.1%). Average pesticide usages in 2011 were 280.9 kg per golf course and $5.4kg\;ha^{-1}$. Frequencies of the residual pesticide detections in green and turf were higher than those in fairway and soil, respectively. Residue of highly toxic pesticides was not detected in golf courses. Ministry of Environment in 2010 has developed the 'golf course pesticide monitoring and management system' which is the advanced online registry for kind and amount of pesticides applied in each golf course. This system is intended for monitoring of the pesticide uses and residual levels and protecting the environmental pollution from pesticides in the golf course. In 2009, management of pesticides in the golf courses became the task of Ministry of Environment, being merged from many federal agency and ministries. The protocol for the site-specific best management practices, on which to base results from the risk assessment, should be set for pesticides in the golf to minimize the environmental impacts.

• Journal of the Microelectronics and Packaging Society
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• v.17 no.4
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• pp.95-100
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• 2010

LED (Light Emitting Diode) is 85% of the applied energy is converted into heat that is already well known. Lately, LED chips increasing the capacity as result delivered to increase the heat of the LED products and module that directly related to life span and degradation. Thus, in industry the high-power LED chip to control the heat generated during the course of the study and the existing aluminum, copper adhesives, and uses MLC (Metal clad laminate) structures using low-cost FR4 and copper CCL (Copper Clad Laminate) to reduce costs by changing to a study being carried out. In this study, using low-cost CCL Class, mounted 1W LED chip to analyze changes in the thermal resistance. In addition, heat dissipation in the CCL to facilitate a variety of thermal via design outside of the heat generated by the LED chip to control and facilitate the optimal structure of the heat dissipation is suggested.

• Radiation Oncology Journal
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• v.13 no.1
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• pp.55-61
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• 1995

Purpose : Despite a development of therapeutic machines and advance in modern radiation therapy techniques, locally advanced cervical carcinoma has shown high rate of local failure and poor survival rate, Combination of chemotherapy and radiotherapy demonstrated benefit in improving local control and possibly the overall survival. Our study was performed to evaluate effect of concurrent chemoradiation on locally advanced uterine cervical cancer. Methods and Materials : Twenty six patients with locally advanced stage(FIGO stage IIB with ${\geq}5cm$ in diameter, III, IVA) were treated with combination of radiation therapy and concurrent cisplatinum between May of 1988 and September of 1993 at our hospital. Radiation therapy consisted of external irradiaton and 1-2 sessions of intracavitary irradiation. Cisplatinum was administered in bolus injection of 25mg/$m^2$ at weekly intervals during the course of external radiation therapy. Results : Of the 26 Patients, twenty-five patients were evaluable for estimation of response. Median follow-up period was 25 months with ranges from 3 to 73 months. Stage IIB, III, and IVA were 16, 5, 4 patients, respectively, Twenty patients were squamous cell carcinoma. Response was noted in all 25 patients: complete response(CR) in 17/25($68\%$), Partial response(PR) in 8/25($32\%$). Of the 24 patients except one who died of sepsis at 3 months follow-up, seventeen patients($70.8\%$) maintained local control in the pelvis: 16/17($94.1\%$) in CR, 1/17($14.3\%$) in PR. Fourteen of the 17 patients with CR are alive disease free on the completion of follow-up. Median survival is 28 months for CR and 15 months for PR. Analysis of 5-year survival by stage shows 11/16($59.8\%$) in IIB, 3/5($60.0\%$) in III, and 1/4($25.0\%$) in IVA. Overall 5-year survival rate was $55.2\%$. Ten patients recurred: 4 at locoregional, 3 in distant metastasis and 3 with locoregional and distant site. Toxicity by addition of cisplatinum was not excessive. Conclusion : Although the result of this study was obtained from small number of patients, it is rather encouraging in view of markedly improved response rate compared with the results of historical group.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2149-2162
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• 2011

Currently practical examination can't function as a practical technique ability evaluation', so there is a contradiction which even though a radiologist passed an examination for license, he has to complete a training course. To improve this problem, this study tried to deduce the most reasonable plan from the analysis of propriety of currently practical examination and what improvement points are. This conduct study was compared and analyzed the performance or practical examination of radiology from leading advanced countries within the samples of 634 radiologists, 56 professors of radiology. From the result of this study, it showed that radiology practical examination was difficult to be substituted by radiology clinical training since there were some critical differences between conditions of domestic and advanced countries. Therefore, the introduction of the radiology practical examination is inevitable and necessary. However the currently practical examination can't evaluate actual practical ability, so we could conclude that converting it into OSCE (objective structured clinical examination) form is essential. From now on, we should consider more about an in-depth study on types of advanced practical examination and how to suggest and present them in order to become an one of the advanced countries for radiologic technologist.

• Radiation Oncology Journal
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• v.31 no.4
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• pp.252-259
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• 2013

Purpose: To report the results of dosimetric comparison between intensity-modulated radiotherapy (IMRT) using Tomotherapy and four-box field conformal radiotherapy (CRT) for pelvic irradiation of locally advanced rectal cancer. Materials and Methods: Twelve patients with locally advanced rectal cancer who received a short course preoperative chemoradiotherapy (25 Gy in 5 fractions) on the pelvis using Tomotherapy, between July 2010 and December 2010, were selected. Using their simulation computed tomography scans, Tomotherapy and four-box field CRT plans with the same dose schedule were evaluated, and dosimetric parameters of the two plans were compared. For the comparison of target coverage, we analyzed the mean dose, $V_{nGy}$, $D_{min}$, $D_{max}$, radical dose homogeneity index (rDHI), and radiation conformity index (RCI). For the comparison of organs at risk (OAR), we analyzed the mean dose. Results: Tomotherapy showed a significantly higher mean target dose than four-box field CRT (p = 0.001). But, $V_{26.25Gy}$ and $V_{27.5Gy}$ were not significantly different between the two modalities. Tomotherapy showed higher $D_{max}$ and lower $D_{min}$. The Tomotherapy plan had a lower rDHI than four-box field CRT (p = 0.000). Tomotherapy showed better RCI than four-box field CRT (p = 0.007). For OAR, the mean irradiated dose was significantly lower in Tomotherapy than four-box field CRT. Conclusion: In locally advanced rectal cancer, Tomotherapy delivers a higher conformal radiation dose to the target and reduces the irradiated dose to OAR than four-box field CRT.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.413-418
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• 2016

Objective: To assess the safety and effectiveness of a mouth-rinse with G-CSF (JiSaiXin, produced by NCPC Biotechnology Co., Ltd) in treating patients with chemotherapy-induced oral mucositis (CIM). Method: A consecutive cohort of patients with advanced cancers and CIM were treated with mouth-rinse G-CSF. All chemotherapy for patients with advanced cancers was adopted from regimens suggested by NCCN guidelines. The mouth-rinse with G-CSF at a dose of 150-300ug plus 100ml-500ml normal saline was started from the time of oral mucositis was confirmed and continuously used for at least 7 days as one course. After at least two courses of treatment, safety and efficacy were evaluated. Results: There were 7 female and 7 male patients with advanced cancer and CIM recruited into this study, including 5 with colorectal, 2 with lung, 1 patient with gastric, 1 with cervical and 1 with pancreatic cancer, as well as 2 patients with diffuse large B cell lymphomas, 1 with nasopharyngeal and 1 with gastric cancer. The median age was 57 (41-79) years. Grade 1 to 2 myelosuppression was observed in 3/14 patients, and Grade 4 myelosuppression in 1/14. Adverse effects on the gastrointestinal tract were documented in 5/14 patients, and were Grade 1 to Grade 3. No treatment related death was documented. Regarding CIM, the median response time to mouth rinse of G-CSF was 2 (1-5) days, and all patients with CIM demonstrated a positive response. Conclusions: Mouth-rinse with G-CSF proved to be safe and effective in treating patients with advanced cancers and CIM. However, further randomized controlled studies should be conducted to clarify the effectiveness of this treatment with other lesions.

• Journal of Hospice and Palliative Care
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• v.9 no.1
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• pp.35-39
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• 2006

A 77-year-old female presented panperitonitis due to advanced gastric ranter during palliative care. In the case of panperitonitis following obstruction or perforation, surgical treatment is vital to avoid fatal sepsis and dehydration. However, the risk of surgery and the residual life of a patient must be carefully considered because of high mortality and complication rate in those patients with advanced disease due to the poor condition. The therapeutic value of aggressive hydration, nasogastric tube insertion, and the use of antibiotics is also questionable. Palliative surgery was not performed on this case, and she passed away peacefully in the presence of family after 4 days of palliative medical care. Here is the appropriate management for this kind of patients we would like to recommend through review of relevant references and long discussions. Firstly, we need to predict survival time using clinical variables. Secondly, considering patient status and risk of surgery, non surgical palliative care such as pain control, transient nasogastric tube insertion, and parenteral hydration is recommended. Minimal use of fluid is desirable to minimize complications such as edema and dyspnea if massive hydration in the beginning of treatment is not proved to be effective. Even though started earlier in the course of disease, discontinuation of antibiotics could be discussed with patients and their caregiver if patient status is not improved.

• Journal of Science Education
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• v.46 no.1
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• pp.80-92
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• 2022

We fitted latent growth models of attitude towards science using the Korea Education & Employment Panel 2004-2007 data with 343 high school students. The growth model show better fit indices compared to the no growth model. The intercept and slope showed significant variances, and thus, we added control variables of the number, ratio of advanced courses, and variety in science elective subjects, and the achievement percentile for middle school. In the conditional growth model, the previous achievement has significant positive effects on the intercept and the ratio of the advanced courses and variety of science subjects show significantly positive effects on the slope. Based on the results, it supports the 2022 Revised Science Curricular that high school credit system should provide students with basic 'Physics,' 'Chemistry,' 'Biology,' and 'Earth Science,' credits in 'general electives', various integrated subjects in 'converged electives', and highly advanced subjects in 'career electives.'

• Journal of Radiation Protection and Research
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• v.15 no.2
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• pp.27-39
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• 1990

Appreciable radiation exposures certainly were occurred in the reactor burn-up, the nuelear fall-out and the surroundings of nuclear installations with radioactive effluents. Therefore, radioactive nuclides is not only potentially hazardous to workers of nuclear power plants and related industrials, but also the wokers who handle radioactive nuclides in biochemical research and nuclear medicine diagnostics. And in the case of occurring the nuclear accidents, the early medical treatment of radiation injury should be necessary but little is established medical procedures to decontaminate the victims of internal contamination of radioactive nuclides in korea. Accordingly, to achieve the basic data for protective roles and medical treatment of radiation injury, the present studies were carrid out to evaluate the decontamination of uranium by the chemical drugs. The results observed were summarized as follows: 1. The combined treatmet group of sodium bicarbonate and saline with uranyl nitrate injection simultaneously and the dithiothreitol group that was administered 30 minutes after uranyl nitrate injection were increased significantly in the change of body weight than uranyl nitrate-only group (P<0.005). 2. All the experimental groups were increased the fluid intake and urine volume on the uranyl nitrate-induced acute renal failure. but the combined treatment group of sodium bicarbonate and saline with uranyl nitrate injection simultaneously and the dithiothreitol group that was administered 30 minutes after uranyl nitrate injection have the higher increment of fluid intake and urine volume (P<0.05). 3. When sodium bicarbonate and saline was treated with uranyl nitrate injection simultaneously. and dithiothreitol was administered 30 minutes after uranyl nitrate injection. there was significantly reduced in BUN concentration (P<0.01). 4. When dithiothreitol was administered 30 minutes after uranyl nitrate injection. there was reduced more significantly on the increment of serum creatinine concentration than that observed in uranyl nitrate-only group(P<0.01). but when the combined treatment of sodium bicarbonate and saline with uranyl nitrate simultaneously, there was still. albeit much less marked. decrease in serum creatinine concentration. 5. The sodium bicarbonate and saline was treated with uranyl nitrate simultaneously and dithiothreitol was administered at 30 minutes after uranyl nitrate were excreted markedly higher urine creatinine concentration than the uranyl nitrate-only group. 6. Uranyl nitrate has been used in experimental animals to produce hydropic degeneration and swelling of proximal tubules, disappearance of microvilli and brush border or necrosis in the kidney and centrilobular necrosis, congestion, and telangiectasia of the liver. When the sodium bicarbonate and saline was treated with uranyl nitrate simultaneously, and dithiothreitol was administered. 30 minutes after uranyl nitrate, there was more marked the protective effect than uranyl nitrate-only group. Finally, if the sodium bicarbonate and saline may administered as quickly as possible each time that some risk for internal contamination, with uranium, and dithiothreitol is administered 30 minutes after uranium contamination, there ameliorates the course of uranyl nitrate-induced acute renal failure.and this effect is assocciated with prevention of uranium (heavy metal)-induced alterations in BUN, serum creatinine, urine creatinine, fluid intake, urine volume and body weight.