• The Korean Journal of Cytopathology
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• v.15 no.1
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• pp.45-51
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• 2004

It is important to recognize the pathognomonic cytologic findings of chordoma, because of overlapping cytologic features between chordoma, chondrshdosarcoma, myxofilbrillary ependymoma, and metastatic adenocarcinoma. We reviewed the cytomorphologic features of 5 cases of chordoma diagnosed by fine needle aspiration cytology at Korean Cancer Center Hospital from 1987 to 2003. Clinical and radiographic findings of each case were reviewed. Four males and one female (29-54 years) had tumors involving the sacrum. Pain was the presenting symptom in 4 cases. The three cases showed moderate to high cellularity. In all cases, typical physaliferous cells with or without cytoplasmic processes were noted. In two cases, the background was myxoid with single scattered cells. Cell clusters showing cord-like arrangement were occasionally seen. The single or clustered cells showed mild cellular pleomorphism with slightly increased nuclear/cytoplasmic ratio. Mitotic figures were not seen. In our review, the recognition of physaliferous cells is the most important feature to diagnose chordoma and to differentiate it from other lesions mimicking chordoma.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2
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• pp.195-206
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• 2020

Although the national radiological emergency response system has been improved by incorporating lessons from the Fukushima nuclear power plant accident and recent domestic natural disasters, it has not fully incorporated these lessons. In addition, it cannot deal with a variety of aftermath of the radiological disaster. Even for the same disaster, the national emergency response system should comply with multiple domestic laws in our country. Furthermore, there are a few discrepancies between the articles of the domestic laws that the national radiological emergency response system should address. Therefore, this study investigates the characteristics of radiological disasters, examines articles on the domestic laws related to the national radiological emergency response system, and analyses the Japanese government's responses to the Fukushima nuclear power plant accident. Based on the results of the review, suggestions for the improvement of the national radiological emergency response system in terms of response organization and framework have been proposed in this study.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.177-179
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• 2002

We have developed a scheduling system for heavy ion radiotherapy considering the condition of three treatment rooms and treatment planning for each patient. This system consists of a database (patient information, treatment method and machine schedule), a schedule for radiotherapy and WEB server. All operation of this system, such as data input, to change and to view the schedule, are performed by using a WEB browser. In order to protect personal information for the patients, access privilege to each information are limited by according to the occupational category. This system is connected with a hospital central information management system (AMIDAS) and an irradiation-managing computer for the heavy ion radiotherapy. A basic information for the patient is got from AMIDAS and the daily schedule sends to the treatment control computer at each treatment room through the irradiation-managing computer every morning. The daily, weekly, monthly schedules in the treatment room and the treatment condition of each patient are shared on the WEB browser with the all participants of the heavy ion therapy. This system could be useful to save a time to generate a treatment schedule and to inform us the most up-to-date treatment schedule and the related information at the same time.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.432-435
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• 2002

We have developed and proposed the heavy ion CT system which consists of fluorescent screen and CCD camera equipped with image intensifier. In our system, we have measured the residual range of particles that passed a phantom and reconstructed the CT image for the distribution of relative stopping power by filtered back projection method with Shepp '||'&'||' Logan filter. The heavy ion $\^$12/C accelerated up to 400 MeV/u by HIMAC (Heavy Ion Medical Accelerator in Chiba) was used. Intensity of the beam output changes like macro pulse, the period being 3.3 sec and the width being 2 sec. The series of data was acquired in synchronizing with the pulse, leading to the improvement of S/N in the CT image. The fundamental performance was experimentally evaluated in the proposed system. The spatial resolution was estimated to be about 1 mm and the density resolution (electron density referred to water) to be about 0.01.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.228-230
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• 2002

The relative electron density resolution was discussed by the noise power spectrum (NPS) in the heavy ion CT image. The heavy ion beam $\^$12/C accelerated up to 400MeV/u by RIMAC was used in this study. The two-dimensional (2-D) NPS in the CT image was obtained from the one-dimensional (1-D) NPS of the measured residual range distribution of water phantom for single projection, and the noise variance in the CT image was calculated from 2-D NPS. The technique used in the reconstruction was the filtered back-projection method with Shepp-Logan filter. The calculated value suggests the result of our previous works using the density resolution phantom, assuming that the relative electron density resolution is twice the standard deviation. Therefore, the estimation of the noise in CT images by 2-D NPS obtained the measured residual range distribution is the useful method.

• Journal of Environmental Health Sciences
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• v.32 no.2 s.89
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• pp.103-110
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• 2006

The present study is designed to analyze reliability and validity of the instruments used to measure job stress of radiological technologists mainly by means of the questionnaires from 'Korean edition of NIOSH check list'. The subjects of this study are 890 radiological technologists active at 44 general hospitals in 16 provinces and cities across the country. The item-total reliability revealed that 10 factors in 6 are the major causes of stress in job life of radiological technologists. The measuring instrument proved to be valid with reliability coefficient of internal consistency by factors being more than 0.7. The factors found to be applicable herewith include limit and authority of job (0.73), cohesion within departments (0.86), resources control (0.81), mental requirements (0.85), job load (0.82), and job stability (0.72). When job autonomy item of causes are modified for proper use to radiological technologists, the measuring instruments are expected to show high reliability. It seems, however, necessary to develop a measuring instrument to analyze and use the validity of related measuring instruments since the reliability here was rated low, with statistical coefficients lower than 0.7 in such factors as job management (0.57), conflicts within departments (-1.13), sense of responsibility for patients (0.66) and usage of education (0.26). As this study was intended to examine reliability and validity of the concepts related to measurement of job stress on the part of radiological technologists, it nay not be proper to apply the results of this study to general use, but is advised to utilize them as basis for developing instruments to verify reliability and validity by comparing with and analyzing other measuring instruments.

• Journal of Microbiology and Biotechnology
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• v.23 no.12
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• pp.1785-1790
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• 2013

The synthetic machinery of ATF4 (activating transcription factor 4) is activated in response to various stress conditions involved in nutrient restriction, endoplasmic reticulum homeostasis, and oxidation. Stress-induced inhibition of proteasome activity triggers the unfolded protein response and endoplasmic reticulum stress, where ATF4 is crucial for consequent biological events. In the current study, we showed that the $NAD^+$-dependent deacetylase, SIRT1, suppresses ATF4 synthesis during proteasome inhibition. SIRT1 depletion via transfection of specific siRNA into HeLa cells resulted in a significant increase in ATF4 protein, which was observed specifically in the presence of the proteasome inhibitor MG132. Consistent with SIRT1 depletion data, transient transfection of cells with SIRT1-overexpressing plasmid induced a decrease in the ATF4 protein level in the presence of MG132. Interestingly, however, ATF4 mRNA was not affected by SIRT1, even in the presence of MG132, indicating that SIRT1-induced suppression of ATF4 synthesis occurs under post-transcriptional control. Accordingly, we propose that SIRT1 serves as a negative regulator of ATF4 protein synthesis at the post-transcriptional level, which is observed during stress conditions, such as proteasome inhibition.

• Journal of radiological science and technology
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• v.30 no.3
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• pp.197-203
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• 2007

The education of radiological technology in Korea is provided lots of information but are low effectiveness of studying due to attach importance to traditional lecture preparing for the national exam of radiological technologist. With a critique about traditional education, a new method of teaching, PBL(Problem based learning) can meet with the workplace through problems and see the real world of occupation objectively taking part in a self-directed learning and cooperative discussion process. And when become a radiological technologist as a member of current society can build up solving problems and ability of communicative competence. We suggest problem-based learning for the education of radiological technologist, hope to see make for cultivating radiological technologist of ability and improve the quality of education.

• Tuberculosis and Respiratory Diseases
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• v.67 no.3
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• pp.234-238
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• 2009

Henoch-$Sch\ddot{o}nlein$ Purpura (HSP) is a systemic vasculitis involving small vessels with the deposition of immune complexes containing IgA and C3, which is characterized by associated skin, joint, renal, and gastrointestinal manifestations. Although there were several causes such as autoimmunity, infection, and drugs, it also can be presented as a form of vasculitidies associated with malignancies. We report a case of HSP developed during treatment for non-small cell lung cancer in a 66-year-old man. Multiple purpuric skin lesions occurred in both legs after the first cycle of chemotherapy, which was diagnosed as HSP by clinical and pathologic examinations. Due to the itching sensation, topical steroid was applied and the patient was improved 3 weeks later without a scheduled change in chemotherapy.

• Journal of the Optical Society of Korea
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• v.20 no.6
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• pp.663-668
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• 2016

In single-photon-emission computed tomography (SPECT) with a pixelated semiconductor detector (PSD), not only pinhole collimators but also parallel-hole collimators are often used in preclinical nuclear-medicine imaging systems. The purpose of this study was to evaluate and compare pinhole and parallel-hole collimators in a PSD. For that purpose, we paired a PID 350 (Ajat Oy Ltd., Finland) CdTe PSD with each of the four collimators most frequently used in preclinical nuclear medicine: (1) a pinhole collimator, and (2) low-energy high-resolution (LEHR), (3) low-energy general-purpose (LEGP), and (4) low-energy high-sensitivity (LEHS) parallel-hole collimators. The sensitivity and spatial resolution of each collimator was evaluated using a point source and a hot-rod phantom. The highest sensitivity was achieved using LEHS, followed by LEGP, LEHR, and pinhole. Also, at a source-to-collimator distance of 2 cm, the spatial resolution was 1.63, 2.05, 2.79, and 3.45 mm using pinhole, LEHR, LEGP, and LEHS, respectively. The reconstructed hot-rod phantom images showed that the pinhole collimator and the LEHR parallel-hole collimator give a fine spatial resolution for preclinical SPECT with PSD. In conclusion, we successfully compared different types of collimators for a preclinical pixelated semiconductor SPECT system.