• Nuclear Engineering and Technology
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• 제55권2호
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• pp.717-724
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• 2023

An essential step in evaluating and comparing the performance of two passive radiation dosimeter types, thermosluminescent (TLD) and optically stimulated luminescence (OSL), used by workers in environments with ionizing radiation for individual radiological monitoring and control of external exposure at various times (cumulative dose for 1 month), is to compare the measured dose accuracy, energy response, and coefficient of variation. In fact this performance study consists in determining the accuracy of both R(10) and R(0.07) which are considered as the ratios of the measured dose (Hp(10) or Hp(0.07)) to the delivered dose (Hp(10) or Hp(0.07)) for each photon energy. The validity of the results of this test is based on the acceptance limits of the ICRP and the international standard IEC-62387. The relative energy response used is normalized to the ¹³⁷Cs 662 keV energy to find which energy response is closest to the ideal case, and the coefficient of variation that allows to determine the statistical fluctuation of the Hp(10) and Hp(0.07) doses. The results of the accuracy test for the OSL and TLD dosimeters are acceptable because they fall within the ICRP limits. For the energy response, the OSL performs better than the TLD for Hp(10) and Hp(0.07), and for the coefficient of variation, the OSL satisfies the requirements of ISO 62387 for both Hp(10) and Hp(0.07), while the TLD satisfies these requirements only for the measurement of Hp (0.07).

• Radiation Oncology Journal
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• 제13권4호
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• pp.339-348
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• 1995

목적 : 위암의 간문맥 임파절 재발로 발생한 악성 폐쇄성 황달치료에 있어서 외부 방사선치료의 효과를 평가해 보고 치료의 결과에 영향을 미칠 수 있는 요인을 알아보고자 하였다. 방법 : 1984년부터 1993년까지 위암의 간문맥 전이로 악성 폐쇄성 황달이 발생한 32명중 3000cGy이상의 방사선량이 조사된 23명을 대상으로 하였다. 치료 결과에 영향을 미칠 수 있는 요인을 알아보기 위하여 방사선량, 황달발생 당시의 질병의 진전정도 및 황달을 일으키는 종피의 위치, 방사선치료 전 총 bilirubin치, 다른 치료와의 병합여부, 원발병소의 수술정도, 재발전 병기를 분석하였다. 외부 방사선치료는 4백만 전자볼트 선형가속기를 이용하여 주 5회, 1회 180-300cGy를 간문맥을 포함하는 부위에 3000cGy-5480cGy(중앙값 3770cGy,TDF 49-86 3420cGy-5580cGy 중앙값 TDF 65, 4140cGy/23fx)가 조사되었다. TDF 65(4140cGy/23fx 이상과 미만을 받은 환자는 각각 13, 10명이었다. 결과 : 전체 환자 23명중 완전관해 13명, 부분관해 5명, 무반응 5명이었다. 전체 환자의 중앙 생존 기간은 5개월이나 완전관해의 경우는 11개월이고 부분관해와 무반응의 경우 각각 3개월이었다. 완전관해를 보인 13명중 6명이 1년 이상 생존하였다. 완전관해의 경우와 부분관해, 무반응과의 생존 기간의 비교에서 의미있는 차이를 보였다(p<0.05). TDF 65인 4140cGy 이상을 받은 13명중 완전관해, 부분관해, 무반응이 각각 10, 2, 1명이었다. 이들 전체환자의 중앙 생존 기간은 9.5개월 이었고 완전관해를 이룬경우 11.5개월 이었다. 그러나 TDF 65(4140cGy/23fx) 미만을 받은 10명중 완전관해, 부분관해, 무반응이 각각 3, 3, 4명 이었고 이들의 중앙 생존 기간은 4.3개월 이었다. 따라서 방사선량이 치료 결과에 영향을 미치며 완전관해를 이루기 위해서는 TOF 65(4140cGy/23fx)이상이 조사되어야 할 것이다. 치료시 질병의 진전정도는 완전관해를 보인 경우 7명이 간문맥이나 췌장 주위에만 국한된 병변을가졌고(5명 담도계하부 병변) 무반응과 부분반응을 보인 모든 환자는 광범위한 질병의 진전이 있거나, 일차병변의 지속상태였다. 질병의 진전상태가 국소적일수록, 담도계하부에 국한되어 있을수록 완전관해의 가능성이 높고 1년 이상 장기생존이 가능할 것으로 추정된다. 완전관해인 경우 10명이 방사선치료후 계속적인 항암화학요법을 받았고 이들중 6명이 1년 이상 생존하였다. 치료 결과에 영향을 미칠 것으로 추정되는 요인으로 방사선량, 황달 발생당시 질병의 진전정도 및 황달을 일으키는 종괴의 위치로 분석 되었다. 외부 방사선치료중 경미한 위장관 부작용(오심, 구토)이 발생하였으나 방사선치료 시행에 영향을 미치지 않았다. 결론 : 위암의 재발로 인해 발생한 악성 폐쇄성 황달환자의 치료에 있어서 TDF 65(4140cGy/23fx) 이상의 외부 방사선치료 단독으로도 만족할 만한 고식적 효과를 이룰수 있고 방사선량과 재발 당시 질병의 진전정도가 치료 결과에 영향을 미칠 수 있는 요인으로 생각 된다.

• BMB Reports
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• 제34권2호
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• pp.123-129
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• 2001

Cellular response to ionizing radiation is affected by cell types, radiation doses, and post-irradiation time. Based on the trypan blue dye exclusion assay in normal oral mucosal cells (OM cells), a 48 h post-irradiation was sufffcient and an adequate time point for the evaluation of radiation sensitivity Its $LD_{50}$ was approximately 1.83 Gy To investigate possible biomarkers useful for the biological radiodosimetry of normal epithelial cells (p53, c-fos, cyclin D1, cdc-2, pRb) EGF receptor phosphorylation and Erk activation were evaluated at different radiation doses and different post-irradiation times. From 0.5 Gy, p53 was accumulated in the nucleus of basal cells of the OM raft culture at 4 h post-irradiation and sustained up to 24 h post-irradiation, which suggests that radiation-induced apoptosis or damage repair was not yet completed. The number of p53 positive cells and biosynthesis of p53 were correlated with radiation doses. Both cyclin D1 and c-fos were only transiently induced within 1 h post-irradiation. Cyclin D1 was induced at all radiation doses. However, cfos induction was highest at 0.1 Gy, approximately 7.3 fold more induction than the control, whose induction was reduced in a reverse correlation with radiation dose. The phosphorylation pattern of cdc-2 and pRb were unaffected by radiation. In contrast to A431 tails overexpressing the EGF receptor approximately 8.5 fold higher than normal epithelial, the OM cells reduced the basal level of the EGF receptor phosphorylation in a radiation dose dependent fashion. In conclusion, among radiation-induced biomolecules, the p53 nuclear accumulation may be considered for the future development of a useful marker far biological radiodosimetry in normal epithelial tissue since it was sustained for a longer period and showed a dose response relationship. Specific c-fos induction at a low dose may also be an important finding in this study It needs to be studied further for the elucidation of its possible connection with the low dose radio-adaptive response.

• 한국식품영양과학회지
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• 제39권2호
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• pp.319-323
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• 2010

본 실험은 기초자료 제공을 위하여 국내에서 재배된 20종의 블루베리에 대한 일반성분, 산도 및 당도 분석과 반응표면분석법을 이용한 블루베리 잼의 관능적 특성 최적화가 수행되었다. 전체 품종에 대한 일반성분의 경우 수분은 75~88%, 단백질은 0.32~0.62%, 지방은 0.12~0.39% 및 탄수화물은 10.18~23.80%의 분포를 나타냈으며 산도 및 당도를 측정한 결과 품종별로 각각 0.82~1.58%와 $7~12^{\circ}Brix$의 분포를 나타내었다. 잼을 가공하는데 있어서 중요한 인자로 작용하는 설탕(200~300 g), 펙틴(0~10 g) 및 구연산 분말(0.0~0.5 g)의 함량을 중심합성실험계획법에 의해 제조된 블루베리 잼의 관능평가를 실시하였으며 반응표면분석법을 이용하여 전반적 기호도에 대한 최적점을 평가한 결과 블루베리, 설탕, 펙틴 및 구연산 분말의 함량이 각각 200 g, 248 g, 4.8 g 및 0.26 g으로 제조되었을 때 가장 높은 기호도를 나타내는 것으로 예측되었다.

• Journal of Microbiology and Biotechnology
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• 제21권4호
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• pp.438-447
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• 2011

Deinococcus radiodurans is extremely resistant to various genotoxic conditions and chemicals. In this study, we characterized the effect of a sublethal concentration (100 ${\mu}M$) of cadmium (Cd) on D. radiodurans using a whole-genome DNA microarray. Time-course global gene expression profiling showed that 1,505 genes out of 3,116 total ORFs were differentially expressed more than 2-fold in response to Cd treatment for at least one timepoint. The majority of the upregulated genes are related to iron uptake, cysteine biosynthesis, protein disulfide stress, and various types of DNA repair systems. The enhanced upregulation of genes involved in cysteine biosynthesis and disulfide stress indicate that Cd has a high affinity for sulfur compounds. Provocation of iron deficiency and growth resumption of Cd-treated cells by iron supplementation also indicates that CdS forms in iron-sulfur-containing proteins such as the [Fe-S] cluster. Induction of base excision, mismatch, and recombinational repair systems indicates that various types of DNA damage, especially base excision, were enhanced by Cd. Exposure to sublethal Cd stress reduces the growth rate, and many of the downregulated genes are related to cell growth, including biosynthesis of cell membrane, translation, and transcription. The differential expression of 52 regulatory genes suggests a dynamic operation of complex regulatory networks by Cd-induced stress. These results demonstrate the effect of Cd exposure on D. radiodurans and how the related genes are expressed by this stress.

• 한국육종학회지
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• 제40권1호
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• pp.15-21
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• 2008

It was previously pointed out that mutation is the ultimate source of variation. Adequate variation is needed for plant breeding if there is a limitation in natural genetic resources. When the ionizing radiation has been known to cause chromosomal and genomic alternations, it is widely used for inducing mutagenesis. The electron beam as an ionizing radiation is the principal physical mutagens that induces mutation and effectively used in plant breeding. Since dose-response relationships of electron beam in plant species are rarely known, we investigated the seed germination rate and early seedling growth of irradiated seeds of creeping bentgrass (Agrostis palustris Huds., cv Penn-A1) with various electron beam irradiating conditions (1, 1.3, 2 MeV at both 0.03 mA and 0.06 mA with dose of 100 Gy (Gray) and 0.03, 1, 1.3, 2 MeV at 0.03 mA with dose of 200 Gy, respectively) using electron accelerator at Korea Atomic Energy Research Institute. The growth parameters in terms of shoot length, primary root length, and secondary root length showed similar response between 0.06 / 1 (mA / MeV) at 100 Gy and 0.03 / 0.3 (mA / MeV) at 200 Gy. Bentgrass seed germination was mainly affected by the intensity of irradiated dose (Gray). Germination rate was lowered as the irradiated dose increased. On the other hand, early seedling growth was mainly governed not by the dose of radiation but by voltage.

• 대한방사선협회지
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• 제25권1호
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• pp.317-323
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• 1999

The response of endothelial cells to ionizing radiation is thought to be an important factor in the overall response of normal tissue. It has been reported that basic fibroblast growth factor (bFGF), a potent mitogen for endothelial cells, protects endoth

• Radiation Oncology Journal
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• 제30권4호
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• pp.218-225
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• 2012

Purpose: The relationship between treatment outcomes, alteration of the expression of biological markers, and tumor volume response during radiotherapy (RT) in patients with uterine cervical cancer was analyzed. Materials and Methods: Twenty patients with cervical squamous cell carcinoma received definitive RT with (n = 17) or without (n = 3) concurrent chemotherapy. Tumor volumes were measured by three serial magnetic resonance imaging scans at pre-, mid-, and post-RT. Two serial punch biopsies were performed at pre- and mid-RT, and immunohistochemical staining for cyclooxygenase (COX)-2 and epidermal growth factor receptor was performed. The median follow-up duration was 60 months. Results: The median tumor volume response at mid-RT (V2R) was 0.396 (range, 0.136 to 0.983). At mid-RT, an interval increase in the distribution of immunoreactivity for COX-2 was observed in 8 patients, and 6 of them showed poor mid-RT tumor volume response ($V2R{\geq}0.4$). Four (20%) patients experienced disease progression after 10 to 12 months (median, 11 months). All 4 patients had poor mid-RT tumor volume response (p = 0.0867) and 3 of them had an interval increase in COX-2 expression. Overall survival (OS) and progression-free survival (PFS) decreased in patients with $V2R{\geq}0.4$ (p = 0.0291 for both). An interval increase in COX-2 expression at mid-RT was also associated with a decreased survival (p = 0.1878 and 0.1845 for OS and PFS, respectively). Conclusion: Poor tumor volume response and an interval increase in COX-2 expression at mid-RT decreased survival outcomes in patients with uterine cervical cancer.

• Radiation Oncology Journal
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• 제38권2호
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• pp.119-128
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• 2020

Purpose: Colorectal cancer is becoming an increasing concern in the middle-aged population of Iran. This study aimed to compare the preliminary results of short-course and long-course neoadjuvant chemoradiotherapy treatment for rectal cancer patients. Materials and Methods: In this clinical trial we recruited patients with rectal adenocarcinoma located from 5 cm to 15 cm above the anal verge. Patients in group I (short-course) received three-dimensional conformational radiotherapy with a dose of 25 Gy/5 fractions in 1 week plus concurrent XELOX regimen (capecitabine 625 mg/㎡ from day 1-5 twice daily and oxaliplatin 50 mg/㎡ on day 1 once daily). Patients in group II (long-course) received a total dose of 50-50.4 Gy/25-28 fractions for 5 to 5.5 weeks plus capecitabine 825 mg/㎡ twice daily. Both groups underwent consolidation chemotherapy followed by delayed surgery at least 8 weeks after radiotherapy completion. The pathological response was assessed with tumor regression grade. Results: In this preliminary report on complications and pathological response, 66 patients were randomized into two study groups. Mean duration of radiotherapy in the group II (long-course) was 5 ± 1 days (range, 5 to 8 days) and 38 ± 6 days (range, 30 to 58 days). The median follow-up was 18 months. Pathological complete response was achieved in 32.3% and 23.1% of patients in the shortcourse and long-course groups, respectively (p = 0.558). Overall, acute grade 3 or higher treatment-related toxicities occurred in 24.2% and 22.2% of patients in group I and II, respectively (p = 0.551). No acute grade 4 or 5 adverse events were observed in either group except one grade 4 hematologic toxicity that was seen in group II. Within one month of surgery, no significant difference was seen regarding grade ≥3 postoperative complications (p = 0.333). Conclusion: For patients with rectal cancer located at least 5 cm above the anal verge, short-course radiotherapy with concurrent and consolidation chemotherapy and delayed surgery is not different in terms of acute toxicity, postoperative morbidity, complete resection, and pathological response compared to long-course chemoradiotherapy.

• Radiation Oncology Journal
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• 제27권2호
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• pp.55-63
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• 2009

목 적: 근치적 치료가 힘든 두경부 진행암 환자들을 대상으로 시행된 소분할 방사선조사의 치료반응 정도를 객관적으로 평가해 보고, 이런 환자들에 대한 적절한 방사선치료 방법을 알아보고자 이 연구를 진행하였다. 대상 및 방법: 두경부에서 발생한 상피세포암종으로 진단되어 1998년부터 2008년까지 원발 병변 또는 림프절 병변에 대해 3 Gy 분할선량으로 고식적 소분할 방사선치료를 받았던 환자 31명을 대상으로 후향적 분석을 하였다. 대상 환자들의 방사선치료 전 컴퓨터단층촬영 영상자료를 통해 종양의 용적을 측정하였고, 이를 방사선치료 종료 후 2~3개월째의 컴퓨터단층촬영 자료와 비교하여 치료반응을 평가하였다. 아울러 소분할 방사선치료로 인한 치료독성의 빈도와 정도를 확인하였고, 전체 생존율 및 무진행 생존율, 그리고 생존율이나 치료반응과 관련된 예후인자들 알아보고자 통계 분석 작업을 하였다. 결 과: 대상 환자들의 평균 연령은 70세였으며, 85%의 경우가 stage 4였다. 종양의 용적은 평균 128.4 cc였고, ECOG 활동점수 상 1점과 2점이 67.7%였다. 총방사선량은 24~45 Gy (중간값 36 Gy)로 2명을 제외한 대부분의 환자가 30 Gy 이상 조사받았으며, 치료기간은 10~25일이었다. 완전반응을 보인 경우가 4명(12.9%)이었고, 19명(61.3%)의 환자에서 부분반응을 보였다. 중간 생존기간은 8.9개월이었으며, 1년 무진행생존율은 12.9%였다. 치료반응 정도에 따른 생존율의 차이를 발견할 수 있었으며, 원발 부위, 병기, 종양의 용적, 방사선치료 범위, 총방사선량 등이 생존율이나 치료반응 정도와 유의한 관련이 있었다. 치료 기간 및 치료 종결 후 grade 4 이상의 치료독성은 없었다. 결 론: 소분할 방사선치료 결과 약 74%의 환자들에서 종양이 줄어드는 것을 객관적으로 확인할 수 있었다. 적절한 분할선량 및 추가 방사선치료가 필요한 환자들의 선별에 있어서는 추가적인 연구가 필요하겠다.