• Title/Summary/Keyword: radiation response

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Effects of 2-deoxy-D-glucose and quercetin on osteoblastic differentiation and mineralization in irradiated MC3T3-E1 cells (2-deoxy-D-glucose와 quercetin이 방사선조사 MC3T3-E1 골모세포주의 분화와 석회화에 미치는 영향)

  • Ahn, Hyoun-Suk;Kim, Kyoung-A;Koh, Kwang-Joon
    • Imaging Science in Dentistry
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    • v.36 no.4
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    • pp.189-198
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    • 2006
  • Purpose: To investigate the in vitro response of MC3T3-E1 osteoblastic cells to X-ray in the presence and absence of 2 deoxy-D-glucose (2-DG) and quercetin (QCT). Materials and Methods: The MC3T3-E1 cells were cultured in an ${\alpha}-MEM$ supplemented with 5 mM 2-DG or $10{\mu}M$ QCT and then the cells were incubated for 12 h prior to irradiation with 2, 4, 6, and 8Gy using a linear accelerator (Mevaprimus, Germany) delivered at a rate of 1.5 Gy/min. At various times after the irradiation, the cells were processed for the analyses of proliferation, viability, cytotoxicity, and mineralization. Results: Exposure of the cells to X-ray inhibited the tritium incorporation, 3-(4, 5-dimethylthiazol-2yl-)-2, 5-diphenyl tetrazolium bromide (MTT)-reducing activity, and alkaline phosphatase (ALP) activity, and caused cytotoxicity and apoptosis in a dose-dependent manner of the X-ray. This effect was further apparent on day 3 and 7 after the irradiation. RA+2-DG showed the decrease of DNA content, cell viability, and increase of cytotoxicity rather than RA. ALP activity increased on day 7 and subsequently its activity dropped to a lower level. 2-DG suppressed the calcium concentration, but visual difference of number of calcified nodules between RA and RA+2-DG was not noticed. RA+QCT showed the increase of DNA content, cell viability, but decrease of cytotoxicity and subG1 stage cells in the cell cycle, and increased calcified nodules in von Kossa staining rather than the RA. ALP activity showed significant increases on day 7 and subsequently its activity dropped to a lower level. Conclusion: The results showed that the 2-DG acted as a radiosensitizing agent and QCT acted as a radiosensitizing agent respectively in the irradiated MC3T3-E1 osteoblast-like cells.

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Measurement of Dose outside a 6 MV Field Edge Using Optically Stimulated Luminescent Nano Dot Dosimeters (광자극형광나노닷선량계를 사용한 6 MV 조사야 가장자리 바깥 선량 측정)

  • Kim, Jongeon;Kim, Wontae
    • Journal of the Korean Society of Radiology
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    • v.8 no.7
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    • pp.449-454
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    • 2014
  • The purpose of this study is(was) to investigate the shielding ratio of 1 mmPb and the off axis ratio outside the field edge at depth of 1 cm from a phantom surface for 6 MV photon beam. A dose of 180 cGy was delivered to a depth of 10 cm for a $10{\times}10cm^2$ and $15{\times}15cm^2$ field in the SAD technique. The off axis ratio was calculated by measuring the dose of optically stimulated luminescent nanoDot dosimeters(OSLnDs) positioned at 2, 4 and 6 cm from the field edge, and the center axis of field. And the shielding ratio of 1 mmPb was calculated by measuring the dose of OSLnDs positioned at 2, 4 and 6 cm from the field edge.. As a result, for a $10{\times}10cm^2$ and $15{\times}15cm^2$ field, the off axis ratios were acquired 0.008-0.023 and 0.011-0.028, respectively. Also the shielding ratios of 1 mmPb were acquired 0.868-0.888 and 0.807-0.842, respectively. These results provide data to protect organs at risk outside the radiation treatment field.

The Study on the Countermeasure Plans about Leakage, Explosion and Fire Accidents of Atmospheric Storage Tank (옥외저장탱크 누출, 폭발 및 화재사고 대응방안에 관한 고찰)

  • Lee, Gab-Kyoo
    • Fire Science and Engineering
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    • v.30 no.6
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    • pp.48-56
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    • 2016
  • A crude oil leakage from a large atmospheric storage tank occurred on 4 April 2014 at 14:50 in Ulsan City, while storing the crude oil in the tank. Emergency Rescue Control Group was deployed in the scene. The company, Fire Service Headquarters and associated agencies got together in Command Post (CP) for discussing an effective corresponding strategy. Many solution plans were drafted in the debate such as power down, stopping the facilities, checking the density of inflammable gas, suppressing oil evaporation, moving the leaked crude oil to a nearby tank and a processing plant and avoiding marine pollution. All the solutions were carried out in cooperation with several agencies and partners. The oil leakage accident was successfully settled up within the process of responding, The Fire Service Headquarters and the company thought that the most important thing was the suppression of oil evaporation and the elimination of ignition source. With Fire Service Headquarters and several agencies' every effort, an explosion and a fire didn't occurred in the scene. This study suggest the improvement of the operating system in Emergency Rescue Control Group in case of petroleum leakage, explosion and fire accidents of atmospheric storage tank, different from a ordinary disaster. Assuming that petroleum leakage in atmospheric storage tank develop the explosion and fire accidents, the spreading speed of the flame and the burning time was experimented and compared with each other. Furthermore, this study concentrates on the effective field response plan prepared for the afterward explosion and fire accidents from petroleum leak in a storage tank, with the database experimented and analyzed in accordance with the angle of radiation in the foam nozzle and the pressure of pumping in a fire engine.

Sapflow Change and Growth Response of Poplar Species under Swine Wastewater Irrigation (양돈폐수처리시 포플러의 수액이동과 생장반응)

  • Lee, Eu Ddeum;Woo, Su Young;Yeo, Jin Kie;Koo, Yeong Bon;Chun, Seung-Hoon
    • Journal of Korean Society of Forest Science
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    • v.98 no.6
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    • pp.740-747
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    • 2009
  • We examined sapflow of two Populus species such as Populus alba ${\times}$ Populus glandulosa and Populus euramericana, grown under Swine wastewater treatment. Sapflow of Populus euramericana was 1.8 times higher than that of Populus alba ${\times}$ Populus glandulosa for 14 months. Sapflow of Populus euramericana and Populus alba${\times}$Populus glandulosa was 4,628L and 2,538L during this period, respectively. Positive relationship between sapflow density and solar radiation and temperature had been shown. Mean temperature, relative humidity and sapflow was strongly associated. There was a decreasing sapflow tendency of the two poplar species during the late October when the mean temperature was decreased. In addition, the data showed high relationship between sapflow and photosynthesis. Two poplar species showed dramatic decrease of sapflow since October.

Thermoregulatory Responses of AM & PM with Body Fat Rate at a Hot Environment (서열환경하에서 체지방률에 따른 오전과 오후의 체온조절반응)

  • Kim, Seong-Suk;Lee, Jung-Sug;Kim, Hee-Eun
    • Fashion & Textile Research Journal
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    • v.7 no.3
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    • pp.315-320
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    • 2005
  • With regard to the fact that temperature of human body remains almost constant at $37^{\circ}C$, changes by circadian variation, this study intended to investigate the effect of circadian rhythm on physiological responses of human body according to body fat rate. Fifteen healthy adult women were recruited for this study and were measured body fat as a method of bio impedance. We organized subjects into three groups ; low body fat group(group L-less than 20% of body fat), medium body fat group(group M-20%~30% of body fat) and high body fat group(group H-more than 30% of body fat). The experiment was carried out in a climate chamber of $32^{\circ}C$, 60% RH with the repeat of 'Exercise' and 'Rest' period. Subjects participated in two experiments, one is morning experiment(called 'AM'), the other is afternoon experiment (called 'PM'). The results of this study are as follows ; As to the variation of rectal temperature, group L and M had a significant difference in the time of the day between AM and PM, but group H had almost the same rectal temperature in the two kinds of experimental time. The reason why group H had a smaller difference in the circadian rhythm of rectal temperature in this study is estimated at the Budd et al.(1991)'s results that body fat had effects on reduction in thermogenesis, radiation, mean skin temperature, and increase in insulation of the tissues. Group M had the highest mean skin temperature in the 'PM'. All the 3 groups didn't have stable values in 'AM'. But it showed more stable in 'PM' than 'AM'. Sweat rate was the highest in group H in both 'AM' and 'PM'. Group M had larger sweat rate in 'PM' than 'AM'. but in group L and H, sweat rate was almost the same in two kinds of time of the day. This result suggests that who have more or less body fat have larger difference in sweat rate between morning and afternoon than who have normal body fat.

Triplet Platinum-based Combination Sequential Chemotherapy Improves Survival Outcome and Quality of Life of Advanced Non-small Cell Lung Cancer Patients

  • Chen, Li-Kun;Liang, Ying;Yang, Qun-Ying;Xu, Fei;Zhou, Ning-Ning;Xu, Guang-Chuan;Liu, Guo-Zhen;Wei, Wei-Dong
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.1863-1867
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    • 2012
  • Background: Maintenance chemotherapy is one strategy pursued in recent years with intent to break through the chemotherapy plateau for advanced non-small cell lung cancer (NSCLC). However, given the toxicity, platinum-based combinations are rarely given for this purpose. We carried out the present prospective study of triplet platinum-based combination sequential chemotherapy in advanced NSCLC to investigate if patients could tolerate and benefit from such intensive treatment. Methods: From Dec 2003 to Dec 2007, 190 stage IIIB and IV NSCLC patients in Sun yat-sen University sequentially received the 3 platinum-based combination (TP-NP-GP) treatment (T: paclitaxol175$mg/m^2$ d1; N: vinorelbine25$mg/m^2$ d1 and 8; G: gemcitabine1$g/m^2$ d1 and 8; P: cisplatin20$mg/m^2$ d1-5; repeated every 3 weeks). Patients were followed up to at least 3 years to obtain survival data. Treatment toxicities and the quality of life (QOL) were assessed during the whole treatment. Results: There were 187 patients evaluable. The TP, NP and GP response rates with sequential use were 42.8% (80/187), 41.1% (65/158) and 28.8% (21/73) respectively. Median survival time was 18.2 months and the 1, 2 and 3 year overall survival (OS) rates were 78.7%, 38.5% and 21.3%. Patients receiving > 6 cycles of chemotherapy had significantly longer OS and TTP (MST 25.3 vs. 14.5 months, TTP 15.1 vs. 9.1 months). The QOL on the whole for the patients was improved after chemotherapy. Conclusions: The sequential chemotherapy strategy with triplet platinum-based combination regimens can improve the survival outcome and the quality of life of advanced non-small cell lung cancer patients.

Study of 4π Compton Suppression Spectrometer by Monte Carlo Simulation (몬테카를로 시뮬레이션을 통한 4π 컴프턴 억제 분광기 연구)

  • Jang, Eun-Sung;Lee, Hyo-Yeong
    • Journal of the Korean Society of Radiology
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    • v.11 no.3
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    • pp.123-129
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    • 2017
  • Compton suppression apparatus using the Compton scattering response, by inhibiting part of the spectrum Compton continuum Compton continuum in the area of the peak analysis of the gamma rays that enables a clearer device. In order to find out the geometry structure of high-purity germanium detector(HPGe) -NaI(TI) and to optimize the effect of movement, Monte Carlo simulation was used to grasp the behavioral characteristics of Compton suppression and compare several layout structures. And applied to the cylinder beaker used for the environmental measurement by using the efficiency according to the distance. For the low-energy source such as 81 keV, the Compton continuum is scarcely developed and the suppression effect is also insignificant because the scattering cross-section of the Compton effect is relatively low. In the spectrum for the remaining energy, it can be seen that the Compton continuum part is suppressed in a certain energy range. Compton suppression effect was not significantly different from positional shift. average reduction factor(ARF) value was about 1.08 for 81 keV and about 1.23 for 1332.4keV energy at the highest value. It can be seen that suppression over the Compton continuum region of the energy spectrum is a more appropriate arrangement. Therefore, it can be applied to various environmental sample measurement through optimized structure.

The Toxicity and Preliminary Clinical Outcomes of Low-Dose Weekly Cisplatin-Based Concurrent Chemoradiotherapy (두경부암에서 저용량 Cisplatin 기반 매주 요법의 항암방사선 동시치료의 독성과 예비 임상 결과)

  • Kim, Tae-Yong;Kim, Kyoung-Ju;Kim, Ki-Hwan;Kim, Ji-Eun;Park, Sun-Won;Oh, So-Won;Jung, Young-Ho
    • Korean Journal of Head & Neck Oncology
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    • v.27 no.1
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    • pp.47-53
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    • 2011
  • Purpose : Concurrent chemoradiotherapy(CCRT) with 3 weekly cisplatin is the standard treatment of locally advanced head and neck cancer(HNC). The aim is to evaluate the efficacy and toxicities of low-dose weekly cisplatin-based CCRT, which was devised to reduce the toxicity of CCRT. Method : We retrospectively analyzed HNC patients who received low-dose weekly cisplatin-based CCRT between 2008 and 2010. Cisplatin 35mg/$m^2$ was weekly given to all patients during radiotherapy. The efficacy was evaluated by the degree of clinical response, treatment failure and survival. The toxicity was evaluated by hematologic toxicities and oral mucositis. Results : A total of 27 patients were analyzed and median age was 59(range 31-81). The ratio of administered dose of radiotherapy and cisplatin to planned dose were 0.98 and 0.93, respectively. Complete remission and partial remission were 73% and 23%, respectively. Treatment failure was observed in 8(30%) patients. 1-year survival rate and 1-year disease free survival rate were 82% and 59%, respectively. Overall survival and progression-free survival did not reach median time. Grade 3/4 anemia, neutropenia, thrombocytopenia and oral mucositis were observed in 11%, 19%, 7% and 32% of patients, respectively. In terms of administered cycles, however, only 1-3% of grade 3/4 hematologic toxicities occurred among total 190 cycles. Severe oral mucositis were statistically associated with old age(p=0.003). Treatment failure had no statistical relation with age, pathology, primary site and stage. Conclusion : Low-dose weekly cisplatin-based CCRT seemed to deliver enough dose of cisplatin and to show low drop-out rate and good efficacy with low hematologic toxicities.

Climatological variability of surface particulate organic carbon (POC) and physical processes based on ocean color data in the Gulf of Mexico

  • Son, Young-Baek;Gardner, Wilford D.
    • Korean Journal of Remote Sensing
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    • v.27 no.3
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    • pp.235-258
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    • 2011
  • The purpose of this study is to investigate climatological variations from the temporal and spatial surface particulate organic carbon (POC) estimates based on SeaWiFS spectral radiance, and to determine the physical mechanisms that affect the distribution of pac in the Gulf of Mexico. 7-year monthly mean values of surface pac concentration (Sept. 1997 - Dec. 2004) were estimated from Maximum Normalized Difference Carbon Index (MNDCI) algorithm using SeaWiFS data. Synchronous 7-year monthly mean values of remote sensing data (sea surface temperature (SST), sea surface wind (SSW), sea surface height anomaly (SSHA), precipitation rate (PR)) and recorded river discharge data were used to determine physical forcing factors. The spatial pattern of POC was related to one or more factors such as river runoff, wind-derived current, and stratification of the water column, the energetic Loop Current/Eddies, and buoyancy forcing. The observed seasonal change in the POC plume's response to wind speed in the western delta region resulted from seasonal changes in the upper ocean stratification. During late spring and summer, the low-density river water is heated rapidly at the surface by incoming solar radiation. This lowers the density of the fresh-water plume and increases the near-surface stratification of the water column. In the absence of significant wind forcing, the plume undergoes buoyant spreading and the sediment is maintained at the surface by the shallow pycnocline. However, when the wind speed increases substantially, wind-wave action increases vertical motion, reducing stratification, and the sediment were mixed downward rather than spreading laterally. Maximum particle concentrations over the outer shelf and the upper slope during lower runoff seasons were related to the Loop Current/eddies and buoyancy forcing. Inter-annual differences of POC concentration were related to ENSO cycles. During the El Nino events (1997-1998 and 2002-2004), the higher pac concentrations existed and were related to high runoffs in the eastern Gulf of Mexico, but the opposite conditions in the western Gulf of Mexico. During La Nina conditions (1999-2001), low Poe concentration was related to normal or low river discharge, and low PM/nutrient waters in the eastern Gulf of Mexico, but the opposite conditions in the western Gulf of Mexico.

Evaluation of Photochemical Reflectance Index (PRI) Response to Soybean Drought stress under Climate Change Conditions (기후변화 조건에서 콩 한발스트레스에 대한 광화학 반사 지수 반응 평가)

  • Sang, Wan-Gyu;Kim, Jun-Hwan;Shin, Pyeong;Baek, Jae-Kyeong;Lee, Yun-Ho;Cho, Jung-Il;Seo, Myung-Chul
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.21 no.4
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    • pp.261-268
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    • 2019
  • Climate change and drought stress are having profound impacts on crop growth and development by altering crop physiological processes including photosynthetic activity. But finding a rapid, efficient, and non-destructive method for estimating environmental stress responses in the leaf and canopy is still a difficult issue for remote sensing research. We compared the relationships between photochemical reflectance index(PRI) and various optical and experimental indices on soybean drought stress under climate change conditions. Canopy photosynthesis trait, biomass change, chlorophyll fluorescence(Fv/Fm), stomatal conductance showed significant correlations with midday PRI value across the drought stress period under various climate conditions. In high temperature treatment, PRI were more sensitive to enhanced drought stress, demonstrating the negative effect of the high temperature on the drought stress. But high CO2 concentration alleviated the midday depression of both photosynthesis and PRI. Although air temperature and CO2 concentration could affect PRI interpretation and assessment of canopy radiation use efficiency(RUE), PRI was significantly correlated with canopy RUE both under climate change and drought stress conditions, indicating the applicability of PRI for tracking the drought stress responses in soybean. However, it is necessary to develop an integrated model for stress diagnosis using PRI at canopy level by minimizing the influence of physical and physiological factors on PRI and incorporating the effects of other vegetation indices.