• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.1
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• pp.36-41
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• 2012

We have been performed on $Co^{60}$ ${\gamma}$-ray irradiation of South Sea cultured pearls, with the absorbed dose of 0.1~100 kGy at room temperature. In addition, it was investigated electron paramagnetic resonance (EPR) and amino acid analysis (AAA) for detection of Gamma irradiated South Sea cultured pearls. It was observed that the irradiated South Sea cultured pearls revealed additional free radical peak such as $CO_2^-$, at a g-factor of $2.001{\pm}0.002$ in EPR spectra. From the amino acid analysis (AAA), it was shown that some of amino acid in the protein of the nacre destroyed after ${\gamma}$-ray; glutamic acid residue by 11.43 %, alanine by 3.11 %, and histidine by 43.75 %. It was useful to detect the irradiated South Sea cultured pearls by EPR measurement in our study.

• Journal of Life Science
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• v.17 no.8 s.88
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• pp.1100-1103
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• 2007

In proton therapy, the Bragg peak is spread out by modulating or degrading the energy of the particles to cover a well-defined target volume at a given depth. Proton transfer plays a key role in a variety of biological, the origin of the elements, tests of the standard model along with applications in medicine, industry and chemical phenomena such as water autoionization, fast proton diffusion, acid-base neutralization. We have studied the radiolysis of various natural resources and have evaluated the antioxidant activity of radiolysis products by proton beam. The most of antioxidant activities of natural resources were decreased with increasing proton fluence. Proton beam induced antioxidant activities both in 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) assay and 2,2'-azinobis(3-ethylbenzot hialozinesulfonic acid) cation radical $(ABTS^{.+})$ assay by a dose dependent fashion.

• Food Science of Animal Resources
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• v.23 no.1
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• pp.50-55
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• 2003

Fresh ground pork was irradiated with the electron beam(3.0 and 5.0 kGy) using 2 different conveyer speeds (10 and 20 ㎐), respectively, in order to determine the effect of conveyer speeds on the development of lipid oxidation and microbial stability. During refrigerated storage, the development of lipid oxidation decreased significantly (p<0.05) with the increase in the electron beam conveyer speed from 10 to 20 ㎐. The ground pork with electron beam inhibited the growth of total aerobic bacteria and mesophiles. The inhibitory effect increased when the electron beam dose increased from 0 to 5.0 kGy. The finding that higher speed(20 ㎐) of electron beam had some antioxidative effect is very promising, however, other means to control the lipid oxidation must also be employed to fully utilize the sterilization effect of electron beam in ground pork.

• Journal of Ginseng Research
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• v.28 no.2
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• pp.78-86
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• 2004

Panax ginseng occupies an important role in the folk medicine of China, Korea and Japan. The present study was undertaken to determine the radioprotective efficacy of ginseng root extract in the liver of Swiss albino mice. The animals were divided into 4 groups. Group I-Only vehicle was administered. Group II-The animals received 10 mg/kg body weight ginseng root extract i.p. for 4 consecutive days. Group III-Animals were irradiated with 8Gy gamma radiation at the dose rate of 1.69 Gy/min at the distance of 80 ems. Group IV-Animals were given by ginseng root extract (10 mg/kg body weight) continuously for 4 days and on 4th day they were irradiated with 8 Gy gamma radiation after 30 min. The animals from above groups were autopsied on 1,3,7,14 and 30 days. Biochemical estimations of phosphatases (acid ＆ alkaline), LDH (lactate dehydrogenase), LPO (lipid peroxidation) and GSH (reduced glutathione) in liver and SGOT (serum glutamate oxaloacetate transaminase), SGPT (serum glutamate pyruvate transaminase) and alkaline phosphatase in serum were done. In ginseng treated group acid phosphatase (ACP), alkaline phosphatase (ALP), LPO and LDH in liver and SGOT, SGPT and alkaline phosphatase in serum did not show any significant alteration. However, a significant increase in GSH content in liver was recorded. In irradiated group there was a significant increase in ACP, ALP and LPO content in liver and SGOT ＆ SGPT in serum was noted. Whereas, a significant decrease was recorded in GSH and LDH activity in liver and alkaline phosphatase activity in serum. Pretreatment of ginseng with radiation significantly alters the biochemical parameters in liver and serum. A significant decline in ACP, ALP activity and LPO content in liver and SGOT and SGPT activity in serum was observed. However, a significant increase in GSH content and LDH activity in liver and ALP activity in serum was estimated. The present study suggests that pretreatment of ginseng before irradiation significantly protects the liver and maintains the enzyme activity.

• Applied Microscopy
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• v.38 no.3
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• pp.185-193
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• 2008

An experimental comparison of the detection properties between imaging plate and film for recording the electron diffraction pattern was carried out on a radiation-sensitive material, an aluminum trihydroxide(gibbsite, ${\gamma}-Al(OH)_3$), through the electron beam irradiation. Because the imaging plate has a wide dynamic range sufficient for recording extremely low- and high-electron intensities, the range of spatial frequency for the diffraction pattern acquired by the imaging plate was extended to two times larger than the range by the film, especially at a low electron dose condition(${\leq}0.1\;e^-/{\mu}m^2$). It is also demonstrated that the imaging plate showed better resolving power for discriminating fine intensity levels even in saturated transmitted beam. Hence, in the respect of investigating the structures of radiation-sensitive materials and cryo-biological specimens, our experimental demonstrations suggest that the imaging plate technique may be a good choice for those studies, which have to use an extremely low electron intensity for recording.

• Radiation Oncology Journal
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• v.6 no.1
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• pp.81-84
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• 1988

Since the entity of postmastectomy lymphangiosarcoma was first reported by Stewart and Treves in 1948, postmastectomy lymphangiosarcoma has become a well recognized, uncommon malignant tumor which occurs in the upper extremity following mastectomy for mammary carcinoma. The postmastectomy lymphangiosarcoma occurred at an average age of 63.9 years and at an average of 10 years and 3 months following mastectomy. The lymphangiosarcoma raised from blood and lymphatic vessel. The histologic appearance has been observed edematous dermiss and dilated lymphatics lining with malignant cells. Most authors recommend radical amputation for treatment, either shoulder disarticulation or forequarter amputation. Other modalities of treatment including radiotherapy were considered as ineffetive. The present report provides a case of the regression of postmastectomy lymphangiosarcoma with chronic lymphedema by external irradiation. Radiation therapy was used as primary therapy. Total tumor dose of 6500 cGy in 9 wks was delivered using 6 MV x-ray and 8 MeV electron.

• Journal of Korean Society on Water Environment
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• v.21 no.1
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• pp.7-13
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• 2005

With the appearance of pathogenic microorganisms, which were resistant to free chlorine, the significant attention to the necessity of powerful alternative disinfection methods such as ozone, chlorine dioxide, LTV irradiation to inactivating pathogens has been increased in water treatment. Among these alternative disinfection methods, ozone is well known as strong biocidal method and the usage of ozone is also increasing in Korea. However, in Korea, there has been no report on the quantitative study of Cryptosporidium parvum with ozone and its evaluation in advanced drinking water treatments. This study reports on the methodology for predicting the ozone inactivation of Cryptosporidium parvum by ozone disinfection in advanced drinking water treatment. The method is based on the fact that a specific inactivation level of microorganisms is achieved at a unique value of ozone exposures, independent of ozone dose and type of water, and quantitatively described by a delayed Chick-Watson model. The required values ${\bar{C}}T$ for 2 log inactivation of Cryptosporidium parvum was $6.0mg/L{\cdot}min$ and $15.5mg/L{\cdot}min$ at $20^{\circ}C$ and $5^{\circ}C$, respectively. From this obtained Cryptosporidium parvum inactivation curves and calculated ${\bar{C}}T$ values of advanced drinking water treatment water in Korea with FIA (Flow injection alaysis), we can predict that water treatment plant can achieve a 1.1~1.8 log inactivation and 0~0.4 log inactivation at $20^{\circ}C$ and $5^{\circ}C$, respectively. This methodology will be useful for drinking water treatment plants which intend to evaluate the disinfection efficiencies of their ozonation process without full scale test and direct experiments with Cryptosporidium parvum.

• Journal of Yeungnam Medical Science
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• v.8 no.2
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• pp.114-120
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• 1991

In electron therapy, low melting point alloy is used for shaping of the field. Electron field shaping material affect the output factor as well as the collimator system. The output factors of electron beams for shaped fields from NELAC-1018 were measured using ionization chamber of Farmer type in water phantom. The output factors of electron beams depend on the incident energy, inherent collimator system and the size of shaped field. Obtained results were followings. 1. In the smaller applicator, output varied extremely according to extent of collimator opening. 2. The higher energy, the output is less varied according to treatment field at small field.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4891-4896
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• 2013

Objective: To separate/enrich tumor stem-like cells from the human esophageal carcinoma cell line OE-19 by using serum-free suspension culture and to identify their biological characteristics and radiation resistance. Methods: OE-19 cells were cultivated using adherent and suspension culture methods. The tumor stem-like phenotype of CD44 expression was detected using flow cytometry. We examined growth characteristics, cloning capacity in soft agar, and radiation resistance of 2 groups of cells. Results: Suspended cells in serum-free medium formed spheres that were enriched for CD44 expression. CD44 was expressed in 62.5% of suspended cells, but only in 11.7% of adherent cells. The suspended cells had greater capacity for proliferation and colony formation in soft agar than the adherent cells. When the suspended and adherent cells were irradiated at 5 Gy, 10 Gy, or 15 Gy, the proportion of CD44+ suspended cells strongly and weakly positive for CD44 was 77.8%, 66.5%, 57.5%; and 21.7%, 31.6%, 41.4%, respectively. In contrast, the proportion of CD44+ adherent cells strongly positive for CD44 was 18.9%, 14.%, and 9.95%, respectively. When the irradiation dose was increased to 30 Gy, the survival of the suspended and adherent cells was significantly reduced, and viable CD44+ cells were not detected. Conclusion: Suspended cell spheres generated from OE-19 esophageal carcinoma cells in serum-free stem medium are enriched in tumor stem-like cells. CD44 may be a marker for these cells.

• Progress in Medical Physics
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• v.27 no.3
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• pp.117-124
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• 2016

Intrafractional motion of patients, such as respiratory motion during radiation treatment, is an important issue in image-guided radiotherapy. The accuracy of the radiation treatment decreases as the motion range increases. We developed a control system for a robotic patient immobilization system that enables to reduce the range of tumor motion by compensating the tumor motion. Fusion technology, combining robotics and mechatronics, was developed and applied in this study. First, a small-sized prototype was established for use with an industrial miniature robot. The patient immobilization system consisted of an optical tracking system, a robotic couch, a robot controller, and a control program for managing the system components. A multi speed and position control mechanism with three degrees of freedom was designed. The parameters for operating the control system, such as the coordinate transformation parameters and calibration parameters, were measured and evaluated for a prototype device. After developing the control system using the prototype device, a feasibility test on a full-scale patient immobilization system was performed, using a large industrial robot and couch. The performances of both the prototype device and the realistic device were evaluated using a respiratory motion phantom, for several patterns of respiratory motion. For all patterns of motion, the root mean squared error of the corresponding detected motion trajectories were reduced by more than 40%. The proposed system improves the accuracy of the radiation dose delivered to the target and reduces the unwanted irradiation of normal tissue.