• 환경생물
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• 제21권1호
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• pp.52-55
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• 2003

There is considerable evidence that ionizing radiation (IR) mediates checkpoint control, repair and cell death. In this study, we have used a high density microarray hybridization approach to characterize the transcriptional response of human breast carcinoma MCF-7 cell line to ${\gamma}$-radiation, such as 4 Gy 4 hr, 8 Gy 4 hr, and 8 Gy 12 hr. We found that exposure to ${\gamma}$-ray alters by at least a $log_2$ factor of 1.0 the expression of 115 known genes. Of the 66 genes affected by ${\gamma}$-radiation, 49 are down-regulated. In our results, the cellular response to irradiation includes induction of the c-jun and EGR1 early response genes. The present work has examined potential cytoplasmic signaling cascades that transduce IR-induced signals to the nucleus. 40S ribosomal protein s6 kinase modulates the activities of the mitogen activated protein kinase (MAPK) and c-Jun $NH_2$-terminal kinase (JNK1) cascades in human monocytic leukemia (U937/pREP4) cells. 14-3-3 family members are dimeric phosphoserine -binding proteins that participate in signal transduction and checkpoint control pathways.

• 한국유기농업학회지
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• 제3권1호
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• pp.11-22
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• 1994

Exposing plant organs to high doses of ionizing irradiation, penetrating into the plant tis-sues and cells, along the track structure of particles, lesions, and sublesions are formed on the molecules and organelles. As a result, disorders in the growth and development as well as chlorophyll-deficiency symptoms occur. The time scale of their reparation, recovery and over compensation during ontogenesis, constitutes a question of high theoretical and practical importanced, with special regard to nuclear fallout. With an aim to model the “ut supra”stated phenomena, the seeds of bean, Echo elit licensed variety, were irradiated by 300 Gy dose of X-ray-irradiation (120 kV:4.5 mA). According to the data obtained, the biosynthesis of photosynthetic pigments, will have been completed by the beginning of flowering. In consequence of the overcompensation of the repairing processes, the organs of plants developed from irradiated seeds, showed a partly differing correlative growth, compared to those of control plants. In order to characterize the vivo response of radiation-injured plants, a new method and approach were used. The changes of the electric capacitance of the plants during their ontogenesis, were continously monitored and recorede via a computer-aided and controlled measurement. In view of the data collected in such a way, the repairing plants may respond more quickly and intensively to the changes of environmental factors.

• Nuclear Engineering and Technology
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• 제53권10호
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• pp.3335-3343
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• 2021

The impact of gamma radiation on a commercial off the shelf microcontroller board has been investigated. Three different tests have been performed to ascertain the radiation tolerance of the device from a nuclear decommissioning deployment perspective. The first test analyses the effect of radiation on the output voltage of the on-board voltage regulator during irradiation. The second test evaluated the effect of gamma radiation on the voltage characteristics of analogue and digital inputs and outputs. The final test analyses the functionality of the microcontroller when using an external, shielded voltage regulator instead of the on-board voltage regulator. The results suggest that a series of latch-ups occurs in the microcontroller during irradiation, causing increased current drain which can damage the voltage regulator if it does not have short-circuit protection. The analogue to digital conversion functionality appears to be more sensitive to gamma radiation than digital and analogue output functionality. Using an external, shielded voltage regulator can prove beneficial when used for certain applications. The collected data suggests that detaching the voltage regulator can extend the lifespan of the platform up to approximately 350 Gy.

• 한국축산식품학회지
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• 제38권6호
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• pp.1196-1202
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• 2018

The objective of this study was to determine the antioxidant activity of gamma-irradiated Asparagus cochinchinensis (Asparagi radix) (Lour.) Merr. Extract (ARE) and its inhibition effect on food lipid oxidation using emulsion-type pork sausage as a model. ARE was prepared from dried Asparagi radix root and ARE solution (1.0 g/mL) was gamma-irradiated with designated doses at 5, 10, and 20 kGy. Antioxidant activity of ARE solution was determined by measuring 1,1-diphenyl-e-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-9-sulphonic acid) (ABTS) radicals. Activities of DPPH and ABTS radicals were decreased, whereas total phenolic contents increased after gamma irradiation with a dose dependence. Addition of gamma-irradiated ARE dose-dependently retarded lipid oxidation of emulsion-type pork sausage during storage at $4^{\circ}C$. These results indicated that gamma-irradiated ARE might have antioxidant activity more than non-irradiated ARE due to increase of the content of polyphenolic compounds by ionizing radiation.

• Radiation Oncology Journal
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• 제19권2호
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• pp.153-162
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• 2001

목적 : 방사선 조사에 의하여 유발되는 세포고사의 신호전달기전, 특히 caspase계 cysteine protease의 활성화, Bcl2 및 Bax 단백질, cytochrome c의 세포질내로의 방출, Fas 와 Fas-L 단백질의 발현양상 등의 조사를 통하여 방사선 조사에 의하여 유발되는 세포고사기전을 규명하고자 하였다. 대상 및 방법 : HL-60 세포주에 6 MV의 X-선을 조사하고 세포생존율, Caspase의 활성도, $Bcl_2$ 및 Bax 단백질, cytochrome c의 세포질내로의 방출여부, 및 Fas 와 Fas-L 단백질의 발현양상을 조사하였다. 결과 : 방사선조사 후 세포의 생존율은 조사선량과 조사 후 시간경과에 따라 감소되었다. 세포고사의 특징인 사다리형 DNA 분절은 방사선조사 4시간 후부터 시간경과에 따라 증가하였으며, 조사선량이 증가할수록 더욱 현저하였다. 방사선조사 후 caspase계 cysteine proteases 중 caspase-2, 3, 6, 8 및 9의 활성화가 시간경과에 따라 증가하였으며, 16 Gy의 방사선량조사 4시간 후에 poly (ADP-ribosyl) polymerase (PARP)의 분절과 Western blot을 이용한 procaspase-3의 분절을 확인함으로서 caspase-3의 활성을 간접적으로 증명할 수 있었다. $Bcl_2$ 단백질은 방사선조사 후 시간경과에 따라 감소하였으며, Bax 단백질은 시간경과에 따라 발현이 증가하는 양상을 관찰할 수 있었다. 방사선조사 후 cytochrome c의 세포질내로의 방출을 확인하였다. 또한 Fas 및 Fas-L 단백질 모두 방사선조사 후 발현이 증가하는 양상을 관찰할 수 있었다. 결론 : HL-60 세포주에서 방사선 조사에 의해 유발되는 세포사멸이 세포고사기전에 의해서 매개됨을 확인하였으며, 이는 세포내 caspase계 cysteine proteases, $Bcl_2$, Bax, 세포질내로의 cytochrome c 방출 그리고 Fas, Fas-L가 관여하는 신호전달경로의 활성화에 의한 것임을 의미하였다.

• 치과방사선
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• 제29권1호
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• pp.105-117
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• 1999

Purpose: Ionizing radiations have been reported as an apoptosis initiating stimulus in various cells and it has established that sustained elevations in [Ca/sup 2+/] can lead to DNA fragmentation by Ca/sup 2+/-dependent endonucleases, ultimately resulting in apoptotic cell death. The previous experiments have been reported by using primarily thymocytes and lymphocytes and the change of [Ca/sup 2+/] was measured only by minutes or hours respectively. We need to evaluate [Ca/sup 2+/] in both several minutes and hours after irradiation of radiation of radiation therapy and verify the apoptotic cells. Materials and Methods: We have measured [Ca/sup 2+/] in human gingival epitheloid cancer cell with 10Gy irradiation, at minutely intervals and hourly intervals using digitized video-intensified fluorescence microscopy and the fluorescent Ca/sup 2+/ indicator dye, fura-2. In order to find out that the transient rise in [Ca/sup 2+/] could induced apoptosis, cells were incubated for 1 hour at 37℃ with TdT enzyme, rinsed and resuspended containing fluorescence and observed under a confocal fluorescence microscope. MTT assay was done to determine cell activity and LDH assay was done to determine the amount of necrotic cells. Results: After irradiation, the transient and temporal increasing of [Ca/sup 2+/] in the KB cells was founded. Though, there was no change in the intracellular [Ca/sup 2+/] at 30 minutes and 2 hours after irradiation. We could detect of DNA fragmented cells at 4 hours after 10Gy irradiated cells. There were no significant differences between 4 hour, 1 day, 3 day cells. There were no significant differences in MTT and LDH assay between the irradiated group and the control group after 4 hours and 1 day. Though after 3 days there were differences in MTT and LDH assay between the irradiated group was significantly decreased than the control group, in LDH assay the number of necrotic cell death of the irradiated was higher than the control group. Conclusion: In KB cells there were incipient and temporal increasing of the [Ca/sup 2+/] with 10Gy irradiation and the apoptosis was founded from 4 hours later which was earlier than seeing of the change of the amount of the cellular ability and necrosis.

• Journal of Dental Anesthesia and Pain Medicine
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• 제23권4호
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• pp.229-236
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• 2023

Background: Local anesthesia has been reliably used to control pain during dental procedures and is important in pediatric dentistry. However, children occasionally complain of prolonged numbness after dental treatment, leading to several problems. Studies conducted to reverse the effect of local anesthesia using phentolamine mesylate and photobiomodulation therapy (PBM) are encouraging but limited. PBM is a type of light therapy that utilizes visible and near-infrared non-ionizing electromagnetic spectral light sources. Hence, this study used this modality to compare the reversal of local anesthesia at two different wavelengths. This study compared the effect of PBM at 660 and 810 nm wavelengths on the reversal of soft tissue local anesthesia using a diode LASER in pediatric dentistry. Method: Informed consent and assent were obtained, and the participants were then divided randomly into three groups of 20 children each: control group-without LASER irradiation, LASER irradiation at 660 nm, and LASER irradiation at 810 nm. Sixty children aged 4-8 years with deciduous mandibular molars indicated for pulp therapy were administered an inferior alveolar nerve block. After 45 min of injection, a duration that was similar to the approximate duration of treatment, they were exposed to 660- and 810-nm LASER irradiation according to their groups until reversal of local anesthesia was achieved. The control group did not undergo LASER irradiation. The reversal of the soft tissue local anesthetic effect was evaluated using palpation and pin prick tests every 15 min, and the LASER irradiation cycle continued until reversal of the soft tissue local anesthesia was achieved. Results: A significant reduction of 55.5 min (27.6%) in the mean soft tissue local anesthesia reversal time was observed after the application of 810 nm wavelength PBM and 69 min (34.7%) after 660 nm wavelength LASER irradiation. Conclusion: PBM with a 660 nm wavelength was more effective in reducing the mean soft tissue local anesthesia reversal duration, and thus can be used as a reversal agent for soft tissue local anesthesia in pediatric dentistry.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.597-600
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• 1998

When a semiconductor(pMOSFET) sensor is exposed to ionizing radiation, electrons/holes are generated in its oxide layer. By the phenomenon of hole traps in oxide layer during their move, the characteristics of semiconductor is changed. This paper describes the output characteristic changes of two kind of pMOSFET(domestic, japan) after C0-60 ${\gamma}$-irradiation on them for their application as radiation accumulated dose monitoring sensors. We found the threshold voltage shifts (VT) of pMOSFETs in proportion to irradiated radiation dose and their linear properties. These results make us confirm that we will be able to develop good accumulated radiation dose monitoring sensors.

• 한국환경과학회지
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• 제14권12호
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• pp.1113-1117
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• 2005

Gamma-ray treatment was used to exterminate nematodes, which were harmful to agriculture When gamma-ray at the dose range of $5\~75$ kGy was irradaidated, nematodes were reduced by $40\~50\%$ When irradiated over 30 kGy, almost nematodes were non-mobile and fluorochromatic reactions showed that $60\;\~80\%$ of nematodes with non-mobility died after irradiation. The results of electron spin resonance spectroscopy suggested that radicals generated by radiolysis could damage to nematodes.

• Applied Biological Chemistry
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• 제1권
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• pp.62-67
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• 1960

1) The variations of flavin adenine dinucleotide(FAD), flavin monomucleotide(FMN) and free riboflavin in control and 600r X-ray irradiated soybean sprout were estimated by the paper chromatographic method. 2) It was found that the formation of riboflavin in soybean sprout was mainly in FAD. 3) There were no great variation of FMN and free riboflavin in soybean sprout during the germination. 4) The moderate amount (600r) of X-ray irradiation accerelated the formation of FAD in soybean sprout during the germination.