• Radiation Oncology Journal
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• 제37권1호
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• pp.1-12
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• 2019

Despite recent innovation in treatment techniques and subsequently improved outcomes, the majority of glioblastoma (GBL) have relapses, especially in locoregional areas. Local re-irradiation (re-RT) has been established as a feasible option for recurrent GBL of all ages with safety, tolerability, and effectiveness both in survival and quality of life regardless of fractionation schedule. To keep adverse effects under acceptable range, cumulative dose limit in equivalent dose at 2 Gy fractions by the linear-quadratic model at α/β = 2 for normal brain tissue (EQD2) with narrow margin should be observed and single/hypofractionated re-RT should be undertaken very carefully to recurrent tumor with large volume or adjacent to the brainstem. Promising outcome of re-operation (re-Op) plus re-RT (re-Op/RT) need to be validated and result from re-RT with temozolomide/bevacizumab (TMZ/BV) or new strategy is expected. Development of new-concept prognostic scoring or risk group is required to select patients properly and make use of predictive biomarkers such as O(6)-methylguanine-DNA methyltransferase (MGMT) promotor methylation that influence outcomes of re-RT, re-Op/RT, or re-RT with TMZ/BV.

• Radiation Oncology Journal
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• 제30권4호
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• pp.182-188
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• 2012

Purpose: For recurrent esophageal cancer after primary definitive radiotherapy, no general treatment guidelines are available. We evaluated the toxicities and clinical outcomes of re-irradiation (re-RT) for recurrent esophageal cancer. Materials and Methods: We analyzed 10 patients with recurrent esophageal cancer treated with re-RT after primary definitive radiotherapy. The median time interval between primary radiotherapy and re-RT was 15.6 months (range, 4.8 to 36.4 months). The total dose of primary radiotherapy was a median of 50.4 Gy (range, 50.4 to 63.0 Gy). The total dose of re-RT was a median of 46.5 Gy (range, 44.0 to 50.4 Gy). Results: The median follow-up period was 4.9 months (range, 2.6 to 11.4 months). The tumor response at 3 months after the end of re-RT was complete response (n = 2), partial response (n = 1), stable disease (n = 2), and progressive disease (n = 5). Grade 5 tracheoesophageal fistula developed in three patients. The time interval between primary radiotherapy and re-RT was less than 12 months in two of these three patients. Late toxicities included grade 1 dysphagia (n = 1). Conclusion: Re-RT of recurrent esophageal cancer after primary radiotherapy can cause severe toxicity.

• Radiation Oncology Journal
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• 제31권4호
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• pp.206-215
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• 2013

Purpose: Re-irradiation (re-RT) is considered a treatment option for inoperable locoregionally recurrent head and neck cancer (HNC) after prior radiotherapy. We evaluated the efficacy and safety of re-RT using Helical Tomotherapy as image-guided intensity-modulated radiotherapy in recurrent HNC. Materials and Methods: Patients diagnosed with recurrent HNC and received re-RT were retrospectively reviewed. Primary endpoint was overall survival (OS) and secondary endpoints were locoregional control and toxicities. Results: The median follow-up period of total 9 patients was 18.7 months (range, 4.1 to 76 months) and that of 3 alive patients was 49 months (range, 47 to 76 months). Median dose of first radiotherapy and re-RT was 64.8 and 47.5 $Gy_{10}$. Median cumulative dose of the two courses of radiotherapy was 116.3 $Gy_{10}$ (range, 91.8 to 128.9 $Gy_{10}$) while the median interval between the two courses of radiation was 25 months (range, 4 to 137 months). The response rate after re-RT of the evaluated 8 patients was 75% (complete response, 4; partial response, 2). Median locoregional relapse-free survival after re-RT was 11.9 months (range, 3.4 to 75.1 months) and 5 patients eventually presented with treatment failure (in-field failure, 2; in- and out-field failure, 2; out-field failure, 1). Median OS of the 8 patients was 20.3 months (range, 4.1 to 75.1 months). One- and two-year OS rates were 62.5% and 50%, respectively. Grade 3 leucopenia developed in one patient as acute toxicity, and grade 2 osteonecrosis and trismus as chronic toxicity in another patient. Conclusion: Re-RT using Helical Tomotherapy for previously irradiated patients with unresectable locoregionally recurrent HNC may be a feasible treatment option with long-term survival and acceptable toxicities.

• Radiation Oncology Journal
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• 제37권1호
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• pp.60-65
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• 2019

Purpose: The quality assurance (QA) chart rounds are multidisciplinary meetings to review radiation therapy (RT) treatment plans. This study focus on describing the changes in RT management based on QA round reviews in a single institution. Materials and Methods: After 9 full years of implementation, a retrospective review of all patients whose charts passed through departmental QA chart rounds from 2007 to 2015. The reviewed cases were presented for RT plan review; subcategorized based on decision in QA rounds into: approved, minor modifications or major modifications. Major modification defined as any substantial change which required patient re-simulation or re-planning prior to commencement of RT. Minor modification included treatment plan changes which didn't necessarily require RT re-planning. Results: Overall 7,149 RT treatment plans for different anatomical sites were reviewed at QA rounds. From these treatment plans, 6,654 (93%) were approved, 144 (2%) required minor modifications, while 351 (5%) required major modifications. Major modification included changes in: selected RT dose (96/351, 27%), target volume definition (127/351, 36%), organs-at-risk contouring (10/351, 3%), dose volume objectives/constraints criteria (90/351, 26%), and intent of treatment (28/351, 8%). The RT plans which required major modification according to the tumor subtype were as follows: head and neck (104/904, 12%), thoracic (12/199, 6%), gastrointestinal (33/687,5%), skin (5/106, 5%), genitourinary (16/359, 4%), breast (104/2387, 4%), central nervous system (36/846, 4%), sarcoma (11/277, 4%), pediatric (7/251, 3%), lymphoma (10/423, 2%), gynecological tumors (2/359, 1%), and others (11/351, 3%). Conclusion: Multi-disciplinary standardized QA chart rounds provide a comprehensive and an influential method on RT plans and/or treatment decisions.

• 수산해양기술연구
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• 제44권4호
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• pp.265-272
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• 2008

Biodegradable polybutylene succinate(PBS) is an environment friendly plastics for fisheries, because it can mitigate the ghost fishing problem caused by gill-net and trap fisheries. To evaluate photodegradability of PBS monofilament in comparison with polyamide(PA) and polyethylene(PE) monofilament, these 3 types of monofilaments were spun and exposed to ultraviolet light(UV) of weather-ometer for 900 hours, and then their modification, crystal structure, strength, and extensibility were analysed. PBS monofilament did not show any crack and maintained its crystal structure after 900 hour exposure to UV whereas PE monofilament began showing cracks and structure modification after 600 hour exposure. Under UV exposure, the strength and extensibility decreased more rapidly in PBS than in PA and PE. We estimate that gill nets made of PBS monofilament can endure for about 1 year. The breaking strength and elongation decreased linearly with the exposure time for the 3 types of monofilaments. The derived regression equations of the residual tenacity(RT, kg/$mm^2$) and the residual extensibility(RE, %) with the exposure time in year(Y) for each monofilament were; PBS : RT=48.598 - 8.6437Y($R^2=0.93$), RE=28.165 - 7.3233Y($R^2=0.98$), P A : RT=59.771 - 8.6437Y($R^2=0.98$), RE=32.198 - 5.2772Y($R^2=0.92$), P E : RT=60.898 - 5.6528Y($R^2=0.98$), RE=11.887 - 0.7188Y($R^2=0.98$).

• The Plant Pathology Journal
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• 제27권2호
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• pp.148-155
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• 2011

Our previous sequence and phylogenetic analyses of the Korean Rice stripe virus (RSV) suggested possible genetic reassortment of RNA segments, but whether this RNA variation contributed to the recent RSV outbreaks in Korea is yet unclear. To further clarify these RSV-RNA segment variations, we developed a reverse transcription-polymerase reaction/restriction enzyme (RT-PCR/RE) analysis-based method. We identified five REs, including DraI, EcoR1, NdeI/AseI, and SpeI, that could differentiate RSV RNA 1-4 subtypes, respectively. Our RT-PCR/RE results provided a clear pattern of RNA reassortment, i.e., different groups of isolates having their RNA segments derived from two to three different RSV ancestors, such as from Eastern and Southwestern Chinese or Japanese M and T isolates. We also found that the migratory small brown planthopper from Eastern China caught by aerial net traps that possesses RSV-RNA3 genotypes corresponds mainly to Eastern China, with a few for Southwestern China based on RT-PCR/RE, sequence and phylogenetic analyses, indicating that RSV populations in Eastern China may also have strong RNA variation. The development of an RE analysisbased method proved a useful epidemiological tool for rapid genotyping and identification of mixed infections by RSV strain and by different subtype.

• 지능정보연구
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• 제1권2호
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• pp.57-71
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• 1995

This paper presents a rule extraction algorithm RE to acquire explicit rules from trained neural networks. The validity of extracted rules has been confirmed using 6 different data sets. Based on experimental results, we conclude that extracted rules from RE predict more accurately and robustly than neural networks themselves and rules obtained from an inductive learning algorithm do. Rule extraction algorithm for neural networks are important for incorporating knowledge obtained from trained networks into knowledge based systems. In lieu of this, the proposed RE algorithm contributes to the trend toward developing hybrid and versatile knowledge-based system including expert systems and knowledge-based decision su, pp.rt systems.

• Journal of Chest Surgery
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• 제13권2호
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• pp.130-133
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• 1980

Since the first report of an operation for prolapsed intervertebral disk by Mixter and Barr[1934], many thousands of operations have been successfully performed without incident. Linton and White in 1945 reported the vascular complication, but perforation of large vessels is rare complication of operation for prolapsed disk. A medical student, aged 22 years, was performed to a disk operation [L4-5, Rt. on May 1977.] From postoperative 10th day, palpitation, generalized edema and substernal pain were noted, and 2 months later, wide pulse pressure [70-80 mmHg], continuous bruit and thrill on the Rt. low abdomen were followed. Aortography revealed arteriovenous fistula between just proximal to abdominal aortic bifurcation and inferior vena cava. So, fistulectomy [Resection of proximal 2 cm of C.I.A., Rt, including fistula opening and end to end anastomosis] was performed on July, 77. During follow up study, remained fistula between Rt. internal lilac artery and lilac vein was found 2 months later. Re-operation [Double ligation of the Rt. internal lilac artery] was don on January 1978. Postop. results were excellent, except impossible to ejaculation.

• 대한치과보철학회지
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• 제48권3호
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• pp.209-214
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• 2010

연구 목적: 본 연구의 목적은 골 유착된 임플란트에 인위적 비틀림을 가한 후 골 유착이 다시 일어나는지, 혹은 일어나지 않는지, 일어난다면 이전의 골유착보다 강화되는지, 약화되는지에 대해 알아보기 위함이다. 연구 재료 및 방법:상업적으로 순수한 티타늄 (commercial pure titanium 99%)으로 직경 3.75 mm, 길이 4 mm의 표면처리 없는 실험용 임플란트를 제작하였다. 3.0 kg이상의 뉴질랜드산 흰색 암컷 토끼 7마리의 좌우 경골에 제작한 임플란트를 2개씩 식립 후, 6주의 골유착 유도 기간 부여 후 비틀림 제거력을 측정한 경우를 I군으로, 다시 임플란트 고정체를 재위치시키고 봉합하여 4주간의 치유기간을 더 두고 측정한 경우를 II군으로 분류하였다. 광학현미경을 이용한 조직 형태학적 분석을 위하여, 1차 비틀림 제거력 측정 직후 1마리의 토끼를 희생시키고, 2차 비틀림 제거력 측정 직후 2마리의 토끼를 희생시켜 각각 4개, 7개의 시편을 제작하여, 광학현미경 (${\times}20$) 분석에서 골-임플란트 접촉 (Bone-Implant contact, BIC, %)비율과 치밀골 부위에 위치하는 임플란트의 나사산 수를 측정하여 CBa (Bone area in the cortical passage)비율을 측정하였다. 비틀림 제거력과 BIC및 CBa비율에서의 I군과 II군의 통계적 유의성 ($\alpha$=.05)을 평가하였다. 결과: 비틀림 제거력 측정에서 I군은 $10.8{\pm}3.6$ NCm로 측정되었으며, II군은 $20.2{\pm}9.7$ NCm로 측정되었으며, I군보다II군의 비틀림 제거력이 평균 98.1% 증가되었다 (P<.05). 조직 형태학적 분석에서 BIC와 CBa 비율은 I군과 II군 사이에 통계적 유의성을 나타내지 않았고 (P>.05), RT/BIC와 RT/CBa 값은 I군과 II군 사이에 통계적 유의성을 나타냈다 (P<.05). 결론: 임플란트 고정체에 의원성 비틀림 동요가 발생한 경우에 초기 골유착을 얻기 위해 필요로 했던 치유기간보다 짧은 기간 내에 이전보다 견고한 골유착을 얻을 수 있을 것으로 생각된다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2001년도 추계학술발표회요약집
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• pp.205.1-205
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• 2001