• Radiation Oncology Journal
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• v.5 no.1
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• pp.13-21
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• 1987

The effect of local hyperthermia of 41 to $43^{\circ}C$ for 30 minutes on radiosensitivity of normal tissue was studied utilizing jejunal crypt microcolony assay. Hyperthermia of this range enhanced the radiation effect and the effect was mainly additive without significant effect on the slopes of cell survival curves. At the isoeffect level of 20 microcolony formation, the thermal enhancement ratio was 1.02, 1.10 and 1.39 for $41^{\circ},\;42^{\circ}\;and\;43^{\circ}C$, respectively. The distribution of microcolony formation along the circumference of jejunum was not uniform, having more colonies around the mesenteric border, and this suggests the effect of uneven cooling by blood circulation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4819-4825
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• 2010

In all of dental ceramics, these materials contained the radio-isotopes with natural abundance ratio. After dental treatment, remained dental ceramics in the oral cavity is caused for human internal dose. In this study, the gross beta activity levels were measured in dental materials including 22 dental ceramics, 1 resin, and 2 cements for estimation of human internal dose. In dental ceramic samples, the obtained results showed that the gross beta activity level varied between 1.317 ~ 2.935 Bq/g and the gross beta activity level was 2.379 Bq/g. And the same level for dentine, opacious dentine, translucent and enamel were 2.479 Bq/g, 2.491 Bq/g, 2.470 Bq/g and 2.069 Bq/g, respectively. The gross beta activity level of temporary resin and cements were negligible, compare to the same level of dental ceramics. The high gross beta activity level observed in opacious dentine code OD-A4 is 2.935 Bq/g thus mainly ascribable to 40K. The reduction of the radiation level of natural radio-isotopes and the improvement of the dental ceramic materials should be required for internal dose reduction.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.16 no.3
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• pp.162-170
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• 2004

On the basis of the radiotracer technology and the related equipments which have been developed for its industrial application through the nuclear long-term research project, a radiotracer study on sediment transport was carried out as a part of the development of the radiotracer technology for a coastal environment. The crystalline material doped with iridium having a similar composition and specific gravity as those of the bedload sand collected from the research area was produced by the oxide-route method. A radioisotope container was specially designed to inject the radiotracer from 1 m above the sea bedload without radioactive contamination during the transport from the nuclear reactor at KAERI. The position data from the DGPS and the radiation measurement data were collected concurrently and stored by means of the application software programmed with the LabVIEW of the National Instrument. The position data was reprocessed to represent the real position of the radiation probe under water and not that of the DGPS antenna on board. The time dependency of the spatial distribution of the sediment was studied in the area through three tracking measurements after the iridium glass was injected. This trial application showed the potential of the radiotracer technology as an important role for maintaining and developing the coastal environment in the future.

• Progress in Medical Physics
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• v.17 no.4
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• pp.201-206
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• 2006

In this study, we have fabricated the noninvasive tube voltage meter which can observe the waveform of tube voltage and measure the tube voltage by using the Intensity of X-ray beam irradiated from radiotherapy simulator and also investigated the feasibility for clinical applications. Two pin photodiodes acting as X-ray detectors were arranged in parallel at the position of ${\pm}1.4cm$ in the y-axis of X-ray field and the aluminum filters with different thickness were placed above them. Using this detector, we could get the ratio ($r_{eff}$) of the relative output voltage which is proportional to the thickness of the filters. And the logarithm of effective peak tube voltage ($InkV_{p,eff}$) was obtained by Victoreen's NERO 6000M used as reference tube voltage meter. From the linear regression analysis of $r_{eff}$ and In $kV_{p,eff}$ the correlation coefficient (r) of linear equation was obtained to be 0.996 for the calibration of the tube voltage meter. Therefore, we suggest that the noninvasive tube voltage meter fabricated in this study can be used for clinical applications due to Its high accuracy.

• Applied Biological Chemistry
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• v.26 no.2
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• pp.82-89
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• 1983

In order to develop a commercial storage method of onions by irradiation combined with natural low temperature, two local varieties of onions, precocious species and late ripening, were stored at natural low temperature storage room ($450{\times}650{\times}250cmH.$; year-round temperature change, $2{\sim}17^{\circ}C$; R.H., $80{\sim}85%$) on batch scale following irradiation with optimum dose level. Precocious and late varieties were all sprouted after five to seven months storage, whereas $10{\sim}15$ Krad irradiated precocious variety was $2{\sim}4%$ sprouted after nine months storage, but sprouting was completly inhibited at the same dose for late variety. The extent of loss due to rot attack after ten months storage were $23{\sim}49%$ in both control and irradiated group of precocious variety but those of late variety were only $4{\sim}10%$. The weight loss of irradiated precocious variety after ten months storage was $13{\sim}16$, while that of late variety was $5.3{\sim}5.9%$ after nine months storage. The moisture content, during whole storage period, of two varieties were $90{\sim}93$ with negligible changes. The total sugar content differed little with varieties and doses immediatly after irradiation, but decreased by the elapse of storage period. 33.6% of its content was decreased in control and 12.5% in irradiated group but $20{\sim}26$ decreased in both control and irradiated group of late variety after nine months storage. No appreciable change was observed immediately after irradiation irrespective of variety and dose, but decreased slightly with storage. Ascorbic acid content of precocious variety was increased slightly with dose immediately after irradiation, but those of late variety decreased slightly. Ascorbic acid content were generally decreased during whole storage period. An economical preservation method of onions appliable to late variety, would be to irradiate onion bulbs at dost range of $10{\sim}15$ Krad followed by storage at natural low temperature storage room.

• The korean journal of orthodontics
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• v.40 no.6
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• pp.421-431
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• 2010

Objective: This study aimed to verify the intra-individual reproducibility of the natural head position (NHP) in adult Korean patients in the centric relation (CR) position and to prove the inter-individual variability of the Frankfurt horizontal (FH) plane and sella-nasion (SN) line compared to the true horizontal line (THL). In addition, the study aimed to investigate the correlations between linear measurements from A-point and B-point to the nasion true vertical line (NTVL) and angular measurements from A-point and B-point to the SN line. Methods: Two lateral cephalograms were taken of 116 subjects (23 males, 93 females) with CR wax bites in a NHP at a one-week interval. Results: Method errors of three variables and intraclass correlation coefficients of six parameters proved the intra-individual reproducibility of NHP (p < 0.001). The angle of the FH to the THL was not significantly different from $0^{\circ}$ (p > 0.05), but it was clinically variable (SD $3.89^{\circ}$) on the inter-individual level. Conversely, the angle of the SN line to the THL was significantly different from $7^{\circ}$ (p < 0.05). Very low correlation was found between the linear measurements and angular measurements of A-point and B-point (p < 0.01). Conclusions: The NTVL could be a useful reference line for assessing the antero-posterior position of the maxilla and mandible of Korean adult patients in NHP and CR.

• The Journal of the Korean bone and joint tumor society
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• v.7 no.4
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• pp.144-150
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• 2001

It is not uncommon for sarcomatous transformation of giant cell tumor of bone to occur after radiation, but osteosarcoma arising from giant cell tumor after surgical treatment is very rare and remains an aggressive form of sarcoma of bone with high mortality rate. We experienced 2 cases in whom a osteosarcoma developed long after benign giant cell tumor of bone was removed surgically from the same site. Malignant transformation was presented at 2 years 1 month and 9 years 8 months each after initial surgery. We describe our experience concerning clinical features, methods of treatment and outcomes of osteosarcoma arising from giant cell tumor.

• The Journal of the Korean bone and joint tumor society
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• v.16 no.1
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• pp.37-41
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• 2010

A hemangioma occurred in the bony epiphysis is extremly rare. A 5-year-old boy visited to our hospital with pain and flexion contracture on the right knee. MRI showed some lesions scattered in the epiphysis of the distal femur and the proximal tibia. Biopsy specimen from the distal femoral epiphysis revealed pathologic findings compatible with hemangioma. On 8 years follow-up, the lesion in the distal femoral epiphysis had been cured, and those in the proximal tibial epiphysis were spontaneously disappeared without surgery. The scanogram shows no leg length discrepancy and angular deformity. We reports a rare case of hemangioma occurred in the bony epiphysis with the results of 8 year follow-up with the review of literatures.

• Proceedings of the KSLP Conference
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• 1996.11a
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• pp.84-84
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• 1996

1986년 10월부터 1996년 8월까지 연세대학교 의과대학 영동세브란스병원 이비인후과에 내원한 환자로서 문진, 이학적검사 및 방사선학적검사에 의하여 양측성대마비로 진단된 47례를 대상으로 성별, 연령, 주증상, 성대마비의 원인 및 치료경과에 대하여 후향적으로 분석하였다. 성별은 남자가 34례(72%), 여자가 13례(28%)였고 연령별로는 20대에서 60대에 걸쳐 비교적 고르게 분포하였으며 평균연령은 46세였다. 주증상이 호흡곤란이었던 경우가 22례(47%)로 가장 많았고 애성이 19례(40%)로 그 다음 순이었다. 성대마비의 원인별로 보면, 중추성이 4례(9%)였고, 나머지는 말초성으로 이중 비수술적 외상에 의한 경우가 15례(32%)로 가장 많았고 수술적 외상이 10례(21%), 특발성이 9례(19%), 기도내 삽관이 5례(11%)였으며, 이외에도 염증성요인에 의한 것이 2례, 갑상선종양에 의한 것이 1례, 그리고 중증근무력증에 의한 것이 1례이었다. 양측성대마비에 대한 치료로서 기관절개술이 13례(28%), 피열연골절제술이 13례(28%)에서 행해졌으며 이중 술후 완전탈관이 가능하였던 경우는 기관절개술을 시행하였던 경우에 6례(46%), 피열연골절제술을 시행하였던 경우에 9례(69%)였고 수술후 완전탈관까지의 기간은 기관절개술의 경우 평균 18개월, 피열연골절제술의 경우 평균 3개월이었다. 이외 보존적 치료가 20례(43%)에서 행해졌으며 이중 2례는 자연치유되었다.

• Korean Journal of Microbiology
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• v.27 no.3
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• pp.297-303
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• 1989

Attempts to isolate the naturally occurring ultra-violet resistant bacteria from environmental sources were made. The isolates, designated No.29, 100, and 107, among numbers of bacterial isolates revealed a remarkable resistance to UV ray, whose degree of resistance in dose/response kinetics was comparable to that of an endospore-former, Bacillus subtilis. In a range of 100-300 $Jm^{-2}$/min of UV irradiation, the isolates exhibited 500-1000 fold resistance compated with E. coli. The isolated appeared to possiss cell-bound pigment of organge or crimson-red. The isolate 29 is spherical in pairs or tetrads, whereas the isolates 100 and 107 are rod. All are Gram-gositive bacteria and seemed to be non-endospore-bearer. A number of biochemical studies pursued on the isolates suggested that they are quite different to each other. Electron microscopic examination and the physiological characters of the isolate 29 suggested that this UV resistant spherical bacterium might be one species of Deinococcus, probably Deinococus radiophilus. Since there is no documents on UV resistant, Gram-positive, non-sporeformer bacillus so far, the isolates 100 and 107 might be turned out as new kinds of UV resistant bacteria occurring in nature by further investigation.