• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.628-634
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• 1999

We have studied, by a nonisotopic in situ end-labeling(ISEL) technique, frequency of apoptosis in the external granular layer(EGL) of the cerebellum of immature mice by ${\gamma}$-rays irradiation from $^{60}Co$ or diagnostic ultrasound exposure. The total number of normal cells and cells showing morphological features of apoptosis were counted. The frequency of apoptotic cells was expressed as a percentage of the total number of cells in EGL. The extent of changes following 200 cGy(1090 cGy/min) was studied at 2, 4, 6, 8, 12, or 24 hours after exposure. The maximal frequency was found 6~8 hours after exposure. The immature mice that received 18, 36, 54, 108, 198, 396 cGy of ${\gamma}$-rays or diagnostic ultrasound(7.5MHz, 4.2mW, $I_{SPTA}=7.9mW/cm^2$, $I_{SPTA}=114.3W/cm^2$) for 10 or 30 minutes were examined 6 hours after irradiation. Measurements performed after ${\gamma}$-ray irradiation showed a dose-related increase in apoptotic cells in each of the mice studied. The dose-response curves were analyzed by a linear-quadratic model ; frequency of apoptotic cell in the EGL was y = $(0.1349{\pm}0.01175)D$+$(-0.0001522{\pm}0.0000334)D^2$+0.048($r^2$ = 0.981, D = dose in cGy). In the experiment of ultrasound exposure, the frequency of apoptotic cell was $0.106{\pm}0.130$(10 minutes exposure) and $0.167{\pm}0.220$(30 minutes exposure). We estimated the relative dose of the yield from the experiment with ultrasound by substituting the yield from ultrasound exposure into the curve from the ${\gamma}$-irradiation. The relative dose of ultrasound exposure compared with ${\gamma}$-irradiation were 0.432 cGy(10 minutes exposure) and 0.885 cGy(30 minutes exposure). We have found that there is no evidence to indicate that diagnostic ultrasound involves a significant risk.

• Journal of Yeungnam Medical Science
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• v.9 no.1
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• pp.102-109
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• 1992

Bone metastases represent an important and frequent clinical problem in patients with advanced cancers. Especially, painful bone metastases are common features in these patients. Radiotherapy is an effective tool for palliative aim of painful metastatic osseous lesions. Various treatment results have been previously reported. The present retrospective study was aimed to evaluate the efficacy of palliative irradiation on pain relief, with the goal of selecting appropriate irradiation dose schedule. Radiotherapy consisted of 5times a week with a various fractional dose between 180 and 400cGy. The response of pain relief and the survival time after completion of radiotherapy are related to total dose and most of the patients have shown a similar response by the end of radiotherapy. The higher dose and the more aggressive multimodality treatment, the better pain control and the longer survival time.

• Radiation Oncology Journal
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• v.18 no.2
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• pp.133-137
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• 2000

Purpose :To investigate whether combined beta-carotene with X-Irradiation has more enhanced radition response than X-irradiation or not, we peformed a experiment about in vitro cytotoxlcity of beta-carotene and/or X-irradiation in the fibrosarcoma cells, tumor growth delay of combined beta-caroten with/or X-irradiation in the mouse fibrosarcoma. Materials and Methods : 2$\%$ emulsion of beta-carotene was serially diluted and used. X-Irradiation was given by 6 MeV linear accelerator. The cytotoxicity of beta-carotene in vitro was evaluated from clonogenic assay. To compare the cytotoxiclty between combined beta-carotene with X-irradiation and X-irradiation group, 2 mg/ml of beta-carotene was contacted to fibrosarcoma (FSall) cells for 1 hour before X-irradiation. For the tumor growth delay, single 20 Gy was given to FSall tumor hearing C3H/N mice whic was classified as beta-crotene with X-irradiation group (n=5) and X-irradiation alone group (n=5). 0.2 ml of 20 mg/kg of beta-carotene were i.p. injected to mice 30 minute before X-irradiation in the beta-crotene with X-irradiation group. The tumor growth delay defined as the time which reach to 1,000 mm$^{3}$ of tumor volume. Results : (1) Cytotoxicity in vitro: 1) survival fraction at beta-carotene concentration of 0.002,0.02,0.2 and 2 mg/ml were 0.69$\pm$0.07, 0.59$\pm$0.08, 0.08$\pm$0.008 and 0.02$\pm$0.006, respectively. 2) each survival fraction at 2, 4, 6 and 8 Gy in the 2 mg/ml of beta-carotene + X-irradiation group were 0.13$\pm$0.05, 0.03$\pm$0.005, 0.01 $\pm$0.002 and 0.009$\pm$0.0008, respectively. But each survival fraction at same irradiation dose in the X-irradiation group were 0.66$\pm$0.05, 0.40$\pm$0.04, 0.11$\pm$0.01 and 0.03$\pm$0.006, respectively(p<0.05). (2) The time which reach to 1,000 mm$^{3}$ of tumor volume of beta-carotene + X-irradiation group and X-irradiation alone group were 18, 19 days, respectively(p>0.05) Conclusion : The contact of beta-caroten to Fsall cells showed mild cytotoxicity which 띤as increased according to concentration. The cytotoxicity of combined beta-carotene with X-irradiation more increased than that of X-irradiation, additionally, And there was significant difference of cytotoxicity between two groups. But there were no significant difference of the growth delay of fibrosarcoma between two groups.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.3
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• pp.196-213
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• 2001

A split beam ultrasonic transducer operating at a frequency of 70 kHz to use in the fish sizing echo sounder was developed and the acoustic radiation characteristics were experimentally analyzed. The amplitude shading method utilizing the properties of the Chebyshev polynomials was used to obtain side lobe levels below -20 dB and to optimize the relationship between main beam width and side lobe level of the transducer, and the amplitude shading coefficient to each of the elements was achieved by changing the amplitude contribution of elements with 4 weighting transformers embodied in the planar array transducer assembly. The planar array split beam transducer assembly was composed of 36 piezoelectric ceramics (NEPEC N-21, Tokin) of rod type of 10 mm in diameter and 18.7 mm in length of 70 kHz arranged in the rectangular configuration, and the 4 electrical inputs were supplied to the beamformer. A series of impedance measurements were conducted to check the uniformity of the individual quadrants, and also in the configurations of reception and transmission, resonant frequency, and the transmitting and receiving characteristics were measured in the water tank and analyzed, respectively. The results obtained are summarized as follows : 1. Average resonant and antiresonant frequencies of electrical impedance for four quadrants of the split beam transducer in water were 69.8 kHz and 83.0 kHz, respectively. Average electrical impedance for each individual transducer quadrant was 49.2$\Omega$ at resonant frequency and 704.7$\Omega$ at antiresonant frequency. 2. The resonance peak in the transmitting voltage response (TVR) for four quadrants of the split beam transducer was observed all at 70.0 kHz and the value of TVR was all about 165.5 dB re 1 $\mu$Pa/V at 1 m at 70.0 kHz with bandwidth of 10.0 kHz between -3 dB down points. The resonance peak in the receiving sensitivity (SRT) for four combined quadrants (quad LU+LL, quad RU+RL, quad LU+RU, quad LL+RL) of the split beam transducer was observed all at 75.0 kHz and the value of SRT was all about -177.7 dB re 1 V/$\mu$Pa at 75.0 kHz with bandwidth of 10.0 kHz between -3 dB down points. The sum beam transmitting voltage response and receiving senstivity was 175.0 dB re 1$\mu$Pa/V at 1 m at 75.0 kHz with bandwidth of 10.0 kHz, respectively. 3. The sum beam of split beam transducer was approximately circular with a half beam angle of $9.0^\circ$ at -3 dB points all in both axis of the horizontal plane and the vertical plane. The first measured side lobe levels for the sum beam of split beam transducer were -19.7 dB at $22^\circ$ and -19.4 dB at $-26^\circ$ in the horizontal plane, respectively and -20.1 dB at $22^\circ$ and -22.0 dB at $-26^\circ$ in the vertical plane, respectively. 4. The developed split beam transducer was tested to estimate the angular position of the target in the beam through split beam phase measurements, and the beam pattern loss for target strength corrections was measured and analyzed.

• Korean Security Journal
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• no.26
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• pp.29-58
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• 2011

Since 11 September 2001, warnings of risk in the nexus of terrorism and nuclear weapons and materials which poses one of the gravest threats to the international community have continued. The purpose of this study is to analyze the aim, principles, characteristics, activities, impediments to progress and developmental recommendation of the Global Initiative to Combat Nuclear Terrorism(GICNT). In addition, it suggests implications of the GICNT for the ROK policy. International community will need a comprehensive strategy with four key elements to accomplish the GICNT: (1) securing and reducing nuclear stockpiles around the world, (2) countering terrorist nuclear plots, (3) preventing and deterring state transfers of nuclear weapons or materials to terrorists, (4) interdicting nuclear smuggling. Moreover, other steps should be taken to build the needed sense of urgency, including: (1) analysis and assessment through joint threat briefing for real nuclear threat possibility, (2) nuclear terrorism exercises, (3) fast-paced nuclear security reviews, (4) realistic testing of nuclear security performance to defeat insider or outsider threats, (5) preparing shared database of threats and incidents. As for the ROK, main concerns are transfer of North Korea's nuclear weapons, materials and technology to international terror groups and attacks on nuclear facilities and uses of nuclear devices. As the 5th nuclear country, the ROK has strengthened systems of physical protection and nuclear counterterrorism based on the international conventions. In order to comprehensive and effective prevention of nuclear terrorism, the ROK has to strengthen nuclear detection instruments and mobile radiation monitoring system in airports, ports, road networks, and national critical infrastructures. Furthermore, it has to draw up effective crisis management manual and prepare nuclear counterterrorism exercises and operational postures. The fundamental key to the prevention, detection and response to nuclear terrorism which leads to catastrophic impacts is to establish not only domestic law, institution and systems, but also strengthen international cooperation.

• Korean Journal of Remote Sensing
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• v.39 no.5_1
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• pp.637-654
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• 2023

In recent years, the number of users has been increasing with the rapid development of earth observation satellites. In response, the Committee on Earth Observation Satellites (CEOS) has been striving to provide user-friendly satellite images by introducing the concept of Analysis Ready Data (ARD) and defining its requirements as CEOS ARD for Land (CARD4L). In ARD, a mask called an Unusable Data Mask (UDM), identifying unnecessary pixels for land analysis, should be provided with a satellite image. UDMs include clouds, cloud shadows, terrain shadows, etc. Terrain shadows are generated in mountainous terrain with large terrain relief, and these areas cause errors in analysis due to their low radiation intensity. previous research on terrain shadow detection focused on detecting terrain shadow pixels to correct terrain shadows. However, this should be replaced by the terrain correction method. Therefore, there is a need to expand the purpose of terrain shadow detection. In this study, to utilize CAS500-4 for forest and agriculture analysis, we extended the scope of the terrain shadow detection to shaded areas. This paper aims to analyze the potential for terrain shadow detection to make a terrain shadow mask for South and North Korea. To detect terrain shadows, we used a Hill-shade algorithm that utilizes the position of the sun and a surface's derivatives, such as slope and aspect. Using RapidEye images with a spatial resolution of 5 meters and Sentinel-2 images with a spatial resolution of 10 meters over the Korean Peninsula, the optimal threshold for shadow determination was confirmed by comparing them with the ground truth. The optimal threshold was used to perform terrain shadow detection, and the results were analyzed. As a qualitative result, it was confirmed that the shape was similar to the ground truth as a whole. In addition, it was confirmed that most of the F1 scores were between 0.8 and 0.94 for all images tested. Based on the results of this study, it was confirmed that automatic terrain shadow detection was well performed throughout the Korean Peninsula.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.26 no.1
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• pp.149-162
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• 2000

Coenzyme Q10 is found in all tissues including skin and it is the well-known coenzyme for mitochondrial enzymes. The electron and proton transfer functions of the quinone ring are of fundamental importance for the oxidative phosphorylation pathway to generate energy in the cells. Coenzyme Q10 has been studied as a potent antioxidant molecule in the skin. It is involved in the skin's response to UVR irradiation. The concentration of this antioxidant in UVR exposed skin is higher than in non-exposed skin. However, recent studies have also shown that coenzyme Q10 is one of the first antioxidants to be depleted when skin is UVR-irradiated. This indicates that coenzyme Q10 is primarily involved in defense mechanisms of the skin. Therefore, we questioned whether coenzyme Q10 shows reulatory effect of melanogenesis. Here we report that coenzyme Q10 inhibits melanin neosynthesis of normal human melanocytes grown in culture, and lightens UVB-induced hyperpigmentation of the guinea pig skin in vivo. We treated human melanocytes with 0.05mM to 0.5mM of coenzyme Q10 for a total of two days. This inhibited melanin neosynthesis of cultured human melanocytes dose-dependently. The inhibitory effect of coenzyme Q10 was as effective as kojic acid or vitamin C on cultured human melanocytes. CoQ10 didn't have direct inhibitory effect on tyrosinase activity in in vitro tyrosine hydroxylase activity To further clarify the effect of coenzyme Q10 on the melanogenesis, we established UVB-induced hyperpigmentation on the shaved backs of brownish guinea pigs. The UVB intensity was 500mJ/$\textrm{cm}^2$ and the total energy dose was 1,500 mJ/$\textrm{cm}^2$. The animals were exposed to UVB radiation one times a week for three consecutive weeks. Coenzyme Q10, kojic acid, Arbutin, vitamin C(1% in vehicle) or vehicle alone as a control were then topically applied daily to the hyperpigmented areas twelve times per week far four successive weeks. The lightening effect was evaluated by visual scoring, chromameter and immunohistochemistry. Coenzyme Q10 had lightening effect on the UVB-induced hyperpigmentation without any other side effects, whereas another compounds showed weak lightening efficacies. Therefore, these results suggest that coenzyme Q10 may be useful for solving physiological hyperpigmenting problems for cosmetic purposes.

• Tuberculosis and Respiratory Diseases
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• v.44 no.4
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• pp.766-775
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• 1997

Background : Primary malignant tumors of the trachea are extremely rare entities and account for a mere 0.1 per cent of all malignancies of the respiratory tract. Because of vague localizing signs, symptoms and a usually negative routine chest film, the patients with tracheal tumors are often treated for asthma or chronic obstructive pulmonary disease for considerable period of time before correct diagnosis. Method : We have made a review of the 17 cases of primary tracheal tumors in recent 15 years. We reviewed the clinical features including history of smoking and respiratory symptoms, the official readings of initial routine chest film, the cytologic examination of sputum, the time of delay in diagnosis, and the response according to the therapeutic modalities. Results : Eight out of 9 patients with squamous cell carcinoma(SCC) were above 50 years old, five out of 6 patients with adenoid cystic carcinoma(ACC) were below 50 years old. The most common location of primary tracheal tumors was the upper one-third of trachea in 8 cases(47%). The most frequent symptoms were dyspnea in 13/17 cases(76%) and then stridor or wheezing, cough. and sputum in order. The routine chest roentgenographic examinations were not helpful to diagnose tracheal carcinoma and the cytologic examinations of sputums were helpful to diagnose tracheal carcinoma in only one case with adenocarcinoma. The mean times of delay in diagnosis of patients with sec and ACC were 5 months and 24.9 months respectively. We had bronchial asthma in 8 cases(47%) and tracheal tumors in 4 cases(23%) as initial clinical impression. Conclusion : We would like to perform more comprehensive diagnostic tools(high KVP technique, the fibroptic bronchoscopic examination, chest CT scan etc.) in patients who had the suggestive points for the tracheal tumorse(1. unexplained hemoptysis or hoarsness, 2. inspiratory wheezing or stridor, 3. wax and waning of dyspnea according to changes of position, 4. progressive asthmatics unresponsive to antiasthmatic therapy) and radical resection of tumor or external radiation therapy with curative aim as possible.

• Journal of Life Science
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• v.30 no.11
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• pp.931-938
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• 2020

Translationally controlled tumor protein (TCTP) is one of the most abundant proteins in various eukaryotic organisms. TCTPs play important roles in cell physiological processes in cancer, cell proliferation, gene regulation, and heat shock response. TCTP is also considered an important factor in the resistance to oxidative stress induced by dithiothreitol or hydrogen peroxide (H₂O₂). Arctic calanoid copepods have a variety of antioxidant defense systems to regulate the levels of potentially harmful reactive oxygen species generated by ultraviolet radiation in the Arctic marine ecosystem. However, information on the antioxidant activity of TCTP in the Arctic Calanus glacialis is still scarce. To understand the putative antioxidant function of the Arctic copepod C. glacialis TCTP (Cg-TCTP), its gene was cloned and sequenced. The Cg-TCTP comprised 522 bp and encoded a 174-amino acid putative protein with a calculated molecular weight of ~23 kDa. The recombinant Cg-TCTP (Cg-r TCTP) gene was overexpressed in Escherichia coli (BL21), and Cg-rTCTP-transformed cells were grown in the presence or absence of H₂O₂. Cg-rTCTP-transformed E. coli showed increased tolerance to high H₂O₂ concentrations. Therefore, TCTP may be an important antioxidant protein related to tolerance of the Arctic copepod C. glacialis to oxidative stress in the harsh environment of the Arctic Ocean.

• Journal of the Korean Society of Radiology
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• v.83 no.6
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• pp.1327-1341
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• 2022

Purpose To evaluate the pattern of use and the perception of digital breast tomosynthesis (DBT) among Korean breast radiologists. Materials and Methods From March 22 to 29, 2021, an online survey comprising 27 questions was sent to members of the Korean Society of Breast Imaging. Questions related to practice characteristics, utilization and perception of DBT, and research interests. Results were analyzed based on factors using logistic regression. Results Overall, 120 of 257 members responded to the survey (response rate, 46.7%), 67 (55.8%) of whom reported using DBT. The overall satisfaction with DBT was 3.31 (1-5 scale). The most-cited DBT advantages were decreased recall rate (55.8%), increased lesion conspicuity (48.3%), and increased cancer detection (45.8%). The most-cited DBT disadvantages were extra cost for patients (46.7%), insufficient calcification characterization (43.3%), insufficient improvement in diagnostic performance (39.2%), and radiation dose (35.8%). Radiologists reported increased storage requirements and interpretation time for barriers to implementing DBT. Conclusion Further improvement of DBT techniques reflecting feedback from the user's perspective will help increase the acceptance of DBT in Korea.