• Environmental Mutagens and Carcinogens
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• v.18 no.2
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• pp.71-76
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• 1998

Exposure to environmental toxicants can cause cellular problems including the interference of DNA repair processes which may lead to the development of cancer. The existence of toxicant-induced DNA repair abnormality was investigated using mice exposed in vivo to genotoxic chemicals and then challenging their exposed lymphocytes in vitro with bleomycin. The repair of bleomycin-induced DNA damage as estimated by the frequency of chromosome aberrations was determined. Our data indicates that the observed aberration frequencies after in vivo exposure to N-methyl-N'-nitro-N-nitnsoguanidine (MNNG) and in vitro challenge with bleomycin are consistently higher than expected. The enhanced response is not due to the induction of chromosome damage by 25 or 50 mg/kg MNNG since the chemical did not cause chromosome aberrations in lymphocytes of these mice. The observed response after the combined exposure to benzo[a]pyrene (BP) and bleomycin was significantly lower than expected with low in vivo doses of BP (50 mg/kg) and then significantly higher than expected with the high doses (200 mg/kg). We interpret our data to indicate that in vivo exposure to genotoxic agents can cause abnormal DNA repair activities. The response is, however, independent of the clastogenic activities of the inducing chemicals, but dependent upon the inducing agents and on the exposure doses.

• Journal of Korean Public Health Nursing
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• v.14 no.1
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• pp.100-113
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• 2000

The purpose of this study is to examine the effect of supportive nursing intervention on patient's response of anxiety in emergency room as the suspected experimental research sequentially designed for the unequal control group. This study collected the data from 100 patients including 50 patients of experimental group and 50 patients of control group in emergency room of the only one university hospital from July 12. to September 30, 1999. This study used questionnaires that Kim, Jung Taek and Shin. Dong Kyun revised the measurement of STAI(State-Trait Anxiety Inventory) of Spielberger(1972) to measure their anxiety with using physical. spiritual. and informative support of the supportive nursing intervention, and measured blood pressure. pulse and respiration by physiological response of anxiety. After then. this study analyzed the frequency and percentage by using SPSS 7.5 program, $x^2-test$, t-test and ANCOVA. The results are as follows: First hypothesis : the point of STAI of experimental group who received the supportive nursing intervention during emergency room staying will be lower than that of control group without the supportive nursing intervention(F=22.943, p=.000). Second hypothesis : the sistolic blood pressure of experimental group who received the supportive nursing intervention during emergency room staying will be lower than that of control group without the supportive nursing intervention(F=42.603. p=.000). Third hypothesis. the diastolic blood pressure of experimental group who received the supportive nursing intervention during emergency room staying will be lower than that of control group without the supportive nursing intervention(F= 18.482, p=.000). Fourth hypothesis: the pulse of experimental group who received the supportive nursing intervention during emergency room staying will be lower than that of control group without the supportive nursing intervention. Fifth hypothesis : The respiration of experimental group who received the supportive nursing intervention during emergency room staying will be lower than that of control group without the supportive nursing intervention. In the above-mentioned result. the supportive nursing intervention was considered to be useful intervention that raised the effect on patient's response of anxiety during emergency room staying.

• Journal of Biomedical Engineering Research
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• v.23 no.2
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• pp.109-117
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• 2002

Electrogastrography(EGG) is a noninvasive method for measuring gastric electrical activity on the abdomen resulting from gastric muscle. EGG signals have a very low frequency range (0.0083 ~0.15 Hz) and extremely low amplitude(10~100 uV). Consequently, EGG signal is easily influenced by other noises. Both finite impulse response(FIR) and infinite impulse response (IIR) filters need high orders or have phase distortions for passing very narrow bandwidth of the EGG signal. In this study, we decomposed EGG signals using a wavelet multiresolution method with Daubechies mother wavelet. The EGG signals were decomposed to seven levels. We reconstructed signal by summing the decomposed signals from level four to seven. To evaluate the performance of the wavelet multiresolution filter(WMF) with simulated EGG signal using two kinds of FIR and four kinds of IIR filters., we used two indices; signal to noise ratio(SNR) and reconstruction squared error(RSE). The SNR of WMF had 9.5, 6.9, and 4.7 dB bigger than that of the other filters at different noise levels, respectively. Also, The RSE of WMF had $1.22{\times}10^6, 1.16{\times}10^6, 1.02{\times}10^6$ smaller than that of the other filters at different noise levels, respectively. The WMF performed better in the SNR and RSE than two kinds of FIR and four kinds of IIR filters.

• Journal of Radiation Protection and Research
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• v.20 no.2
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• pp.97-102
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• 1995

Adaptive response induced by low dose ${\gamma}-ray$ irradiation in human peripheral lymphocytes was examimed. Human lymphocytes were exposured to low dose of ${\gamma}-ray$ (priming dose, 0.01Gy) followed by high dose (challenging dose, 1.5Gy) after various time intervals (4, 7, 20 hours). Frequencies of micronuclei were enumerated in both primed and unprimed groups. Maximum reduction in frequency of micronuclei was observed when challenging dose irradiation was followed by priming dose after 4hr incubation period. When challenging doses were irradiated 7 or 20hr after priming dose, frequencies of micronuclei were reduced slighty. However, these reduction were not statistically significant. In this study, human peripheral lymphocytes were irradiated at Go phase and they showed adaptive response induced by low dose radiation. Since micronucleus assay is relatively simpler and faster than other methods, it may be a good tool for evaluating radiation-induced adaptive responses.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.6
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• pp.367-374
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• 2019

We investigate the effect of soil-structure interaction (SSI) on the response of LNG storage tanks to vertical seismic excitation depending on the type of foundation. An LNG storage tank with a diameter of 71 m on a clay layer with a thickness of 30 m upon bedrock, was selected as an example. The nonlinear behavior of the soil was considered in an equivalent linear method. Four types of foundation were considered, including shallow, piled raft, and pile foundations (surface and floating types). In addition, the effect of soil compaction within the group pile on the seismic response of the tank was investigated. KIESSI-3D, an analysis package in the frequency domain, was used to study the SSI and the stress in the outer tank was calculated. Based on an analysis of the numerical results, we arrived at three main conclusions: (1) for a shallow foundation, the vertical stress in the outer tank is less than the fixed base response due to the SSI effect; (2) for foundations supported by piles, the vertical stress can be greater than the fixed base stress due to the increase in the vertical impedance due to the piles and the decrease in radiation damping; and (3) soil compaction had a miniscule impact on the seismic response of the outer tank.

• Korean Journal of Head & Neck Oncology
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• v.24 no.1
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• pp.26-32
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• 2008

Purpose：Hypopharyngeal carcinoma is usually diagnosed as an advanced disease after an asymptomatic beginning, and it is related to a high frequency of lymph node metastases. An eventual negative outcome may occur not only because of possible locoregional failures but also for frequent distant metastases. Thus, the efficacy of induction chemotherapy followed by radiation therapy, with regards to the response, survival rate and complications for locally advanced hypopharyngeal carcinoma patients, was examined. Methods and Materials：Since July 1998 to February 2001, 18 patients having locally advanced hypopharyngeal carcinoma were treated with induction chemotherapy followed by radiation therapy, and the results were retrospectively analyzed. The regimen of the induction chemotherapy was the 5-flurouracil(5-FU, 1,000mg/$m^2$ daily for 5 consecutive days) and cisplatin(100mg/$m^2$ on day 1) combination at 3-week intervals for 2 cycles. The total radiation dose for the primary tumor and metastatic lymph nodes was 68.4-72.0Gy(median：70.2Gy) Results：The 3-year overall survival rate and disease free survival rate were 31.3% and 22.2%, respectively. In 6 patients(33.3%), preservation of the larynx for over 3 years was possible. After the induction chemotherapy and radiotherapy, a complete response was noted in 14 patients(77.8%), and a partial response in 4 patients (22.2%), with an overall response rate of 100%. Conclusion：Induction chemotherapy followed by radiation therapy is an effective treatment and larynx preservation rate was 33% in patients with locally advanced hypopharyngeal carcinoma in our report.

• Clinical and Experimental Emergency Medicine
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• v.3 no.3
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• pp.175-180
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• 2016

Objective Combination of ${\beta}_1-adrenergic$ receptor (AR) blockade and ${\beta}_2-AR$ activation might be a potential novel therapy for treating heart failure. However, use of ${\beta}-AR$ agonists and/or antagonists in the clinical setting is controversial because of the lack of information on cardiac inotropic or chronotropic regulation by AR signaling. Methods In this study, we performed hemodynamic evaluation by examining force frequency response (FFR), Frank-Starling relationship, and response to a non-selective ${\beta}-AR$ agonist (isoproterenol) in hearts isolated from 6-month-old transgenic (TG) mice overexpressing ${\beta}_1-$ and ${\beta}_2-ARs$ (${\beta}_1-$ and ${\beta}_2-AR$ TG mice, respectively). Results Cardiac physiologic consequences of ${\beta}_1-$ and ${\beta}_2-AR$ overexpression resulted in similar maximal response to isoproterenol and faster temporary decline of positive inotropic response in ${\beta}_2-AR$ TG mice. ${\beta}_1-AR$ TG mice showed a pronounced negative limb of FFR, whereas ${\beta}_2-AR$ TG mice showed high stimulation frequencies with low contractile depression during FFR. In contrast, Frank-Starling relationship was equally enhanced in both ${\beta}_1-$ and ${\beta}_2-AR$ TG mice. Conclusion Hemodynamic evaluation performed in the present showed a difference in ${\beta}_1-$ and ${\beta}_2-AR$ signaling, which may be due to the difference in the desensitization of ${\beta}_1-$ and ${\beta}_2-ARs$.

• Korean Journal of Remote Sensing
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• v.24 no.2
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• pp.99-106
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• 2008

A synthetic aperture radar (SAR) system is of great interest in many fields of civil and military applications because of all-weather and luminance free imaging capability. SAR image quality parameters such as spatial resolution, peak to sidelobe ratio (PSLR), and integrated sidelobe ratio (ISLR) can be normally estimated by modeling of impulse response function (IRF) which is obtained from various system design parameters such as altitude, operational frequency, PRF, etc. In modeling of IRF, however, background clutter environment surrounding the IRF is generally neglected. In this paper, analysis method for SAR mage quality is proposed in the real background clutter environment. First of all, SAR raw data of a point scatterer is generated based on various system parameters. Secondly, the generated raw data can be focused to ideal IRF by range Doppler algorithm (RDA). Finally, background clutter obtained from image of currently operating SAR system is applied to IRF. In addition, image quality is precisely analyzed by zooming and interpolation method for effective extraction of IRF, and then the effect of proposed methodology is presented with several simulation results under the assumption of estimation error of Doppler rate.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.6
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• pp.347-352
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• 2018

This study proposes seismic response analysis technique of a two-mass rack system which sustains heavy loads with frictional behavioral characteristics. In order to deal with the nonlinear frictional characteristics of the mass on the rack system, the equations of motion of the system has been derived and the appropriate numerical simulation technique has been developed. In order to examine the seismic performance of the proposed system, we consider two parameters that are expected to have great influence on the seismic performance of the system. One is the ratio of the two masses of the load and the rack structure, and the other is the friction coefficient between rack and loaded mass. A number of numerical simulations of the seismic response of structures with various natural frequencies for both parameters have been performed in order to investigate the seismic safety of the rack structures. From the simulated results. it is observed that the maximum displacement of the rack system tends to decrease drastically as the natural frequency of the structure increases regardless of the two parameters of mass ratio and friction coefficient. The proposed study provides important reference data to guarantee the seismic safety of the rack system by considering nonlinear frictional behavior of the loaded mass.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.3
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• pp.155-164
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• 2019

In this study, the soil-structure interaction(SSI) effect on the seismic response of LNG storage tanks was investigated according to the type of foundation. For this purpose, a typical of LNG storage tank with a diameter of 71m, which is constructed on a 30m thick clay layer over bedrock was selected, and nonlinearity of the soil was taken into account by the equivalent linearization method. Four different types of foundations including shallow foundation, piled raft foundation, and pile foundations(surface and floating types) were considered. In addition, the effect of soil compaction in group piles on seismic response of the tank was investigated. The KIESSI-3D, which is a SSI analysis package in the frequency domain, was used for the SSI analysis. Stresses in the outer tank, and base shear and overturning moment in the inner tank were calculated. From the comparisons, the following conclusions could be made: (1) Conventional fixed base seismic responses of outer tank and inner tank can be much larger than those of considering the SSI effect; (2) The influence of SSI on the dynamic response of the inner tank and the outer tank depends on the foundation types; and (3) Change in the seismic response of the structure by soil compaction in the piled raft foundation is about 10% and its effect is not negligible in the seismic design of the structure.