• Korean Journal of Digital Imaging in Medicine
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• v.13 no.3
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• pp.139-144
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• 2011

The purpose of this report is recommending a standard indicator which reflects the radiation exposure that is incident on a detector after every exposure event and that reflects the noise levels present in the image data. The experiment was performed with mobile digital X-ray unit and used a acrylic phantom for exposure index measurement. Exposure modality was kVp, mAs, SID. After every exposure, make a data sheet for characteristic curve of detector response. The equipment performed Mobile digital X-ray unit provide the user with values ralated to the incident exposure(air kerma)to the digital detector. They are showed as a logarithmic function shaped. As a result, DEI means a relative measure of exposure to the detector, as compared to the expected exposure for a particular anatomical view. Radiographic technique is the combination of factors used to exposure an anatomical part to produce a high quality radiography and technique charts used most commonly by radiographers to produce consistently exposure level which patient dose can be kept acceptably low.

• Korean Journal of Animal Reproduction
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• v.17 no.1
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• pp.49-56
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• 1993

Mouse mammary epithelial cells(NMuMG) were plated onto 24 well phates(100,000 cells/well), in DMEM supplemented with 10% fetal calf serum. After serum starvation for 24 hours, EGF)0~100ng/ml) was added simultaneously with IGF-I(10ng/ml), 1$\mu$M photoreactive cAMP(4,5-dimethoxy-2-nitrobenzyl adenosine-3',5' cyclic monophosphate, DMNB) or IGF-I plus DMNB. After 2 hours, the cells were expposed to UV light(300nm, 3 second pulse0 in order to activate DMNB which induces a rapid transient increase in intracellular cAMP upon UV irradiation. DNA synthesis was estimated as incorporation of 3H-thymidine into DNA(1 hour pulse with 1$\mu$Ci/ml, 18~19 hours after UV exposure). Without IGF-I or DMNB, EGF(10 or 100ng/ml) increased DNA synthesis from 8,362 dpm/well in control to 16,345 or 18,684 dpm/well with EGF(pooled SE=1,239 dpm/well, P<0.05). IGF-I or IGF-I plus DMNB alone increased DNA synthesis from 8,362 dpm/well in control to 17,307 or 20,427 dpm/well, respectively(P<0.05). Addition of IGF-I, DMNB or IGF-I plus DMNB into 0~100ng/ml EGF did not significantly change the shape of dose response curve of EGF alone. In other experiment, EGF or IGF-I plus DMNB into 10ng/ml EGF group exhibited interaction effect in DNAsynthesis [EGF(10ng/ml)=18,497; IGF-I＋EGF=22,837; DMNB＋EGF=20,658 ; IGF-I＋DMNB＋EGF=29,658, pooled SE=1,055, P<0.05]. These results indicate that simultaneous activation of EGF, IGF-I and intracellular cAMP interact in DNA synthesis of mouse mammary epithelial cells.

• Clinical and Experimental Pediatrics
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• v.60 no.11
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• pp.353-358
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• 2017

Purpose: To develop and evaluate a simple screening tool to assess hearing loss in newborns. A derived score was compared with the standard clinical practice tool. Methods: This cohort study was designed to screen the hearing of newborns using transiently evoked otoacoustic emission and auditory brain stem response, and to determine the risk factors associated with hearing loss of newborns in 3 tertiary hospitals in Northern Thailand. Data were prospectively collected from November 1, 2010 to May 31, 2012. To develop the risk score, clinical-risk indicators were measured by Poisson risk regression. The regression coefficients were transformed into item scores dividing each regression-coefficient with the smallest coefficient in the model, rounding the number to its nearest integer, and adding up to a total score. Results: Five clinical risk factors (Craniofacial anomaly, Ototoxicity, Birth weight, family history [Relative] of congenital sensorineural hearing loss, and Apgar score) were included in our COBRA score. The screening tool detected, by area under the receiver operating characteristic curve, more than 80% of existing hearing loss. The positive-likelihood ratio of hearing loss in patients with scores of 4, 6, and 8 were 25.21 (95% confidence interval [CI], 14.69-43.26), 58.52 (95% CI, 36.26-94.44), and 51.56 (95% CI, 33.74-78.82), respectively. This result was similar to the standard tool (The Joint Committee on Infant Hearing) of 26.72 (95% CI, 20.59-34.66). Conclusion: A simple screening tool of five predictors provides good prediction indices for newborn hearing loss, which may motivate parents to bring children for further appropriate testing and investigations.

• Clinical and Experimental Pediatrics
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• v.59 no.10
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• pp.408-413
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• 2016

Purpose: This study investigated predictors of unresponsiveness to second-line intravenous immunoglobulin (IVIG) treatment for Kawasaki disease (KD). Methods: This was a single-center analysis of the medical records of 588 patients with KD who had been admitted to Asan Medical Center between 2006 and 2014. Related clinical and laboratory data were analyzed by univariate and multivariate logistic regression analyses. Results: Eighty (13.6%) of the 588 patients with KD were unresponsive to the initial IVIG treatment and received a second dose. For these 80 patients, univariate analysis of the laboratory results obtained before administering the second-line IVIG treatment showed that white blood cell count, neutrophil percent, hemoglobin level, platelet count, serum protein level, albumin level, potassium level, and C-reactive protein level were significant predictors. The addition of methyl prednisolone to the second-line regimen was not associated with treatment response (odds ratio [OR], 0.871; 95% confidence interval [CI], 0.216-3.512; P=0.846). Multivariate analysis revealed serum protein level to be the only predictor of unresponsiveness to the second-line treatment (OR, 0.160; 95% CI, 0.028-0.911; P=0.039). Receiver operating characteristic curve analysis to determine predictors of unresponsiveness to the second dose of IVIG showed a sensitivity of 100% and specificity of 72% at a serum protein cutoff level of <7.15 g/dL. Conclusion: The serum protein level of the patient prior to the second dose of IVIG is a significant predictor of unresponsiveness. The addition of methyl prednisolone to the second-line regimen produces no treatment benefit.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.5
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• pp.413-421
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• 2001

An impaired smooth muscle cell (SMC) relaxation of coronary artery by alteration of $K^+$ channels would be the most potential explanation for reduced coronary reserve in left ventricular hypertrophy (LVH), however, this possibility has not been investigated. We performed morphometrical analysis of the coronary artery under electron microscopy and measured $Ca^{2+}-activated\;K\;(K_{Ca})$ currents and delayed rectifier K $(K_{dr})$ currents by whole-cell and inside-out patch-clamp technique in single coronary arterial SMCs from rabbits subjected to isoprenaline-induced cardiac hypertrophy. Coronary arterial SMCs underwent significant changes in ultrastructure. The unitary current amplitude and the open-state probability of $K_{Ca}$ channel were significantly reduced in hypertrophy without open-time and closed-time kinetic. The concentration-response curve of $K_{Ca}$ channel to $Ca^{2+}$ is shifted to the right in hypertrophy. The reduction in the mean single channel current and increase in the open channel noise of $K_{Ca}$ channel by TEA were more sensitive in hypertrophy. $K_{dr}$ current density is significantly reduced in hypertrophy without activation and inactivation kinetics. The sensitivity of $K_{dr}$ current on 4-AP is significantly increased in hypertrophy. This is the first study to report evidence for alterations of $K_{Ca}$ channels and $K_{dr}$ channels in coronary SMCs with LVH. The findings may provide some insight into mechanism of the reduced coronary reserve in LVH.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.1
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• pp.83-91
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• 2020

The evaluation of the compression behavior of the cushioning material is of importance to achieve appropriate packaging design. In order to change packaging design from polymeric-based to more eco-friendly cellulose-based nire effectively, comparative study on the compression behavior between these two packaging materials is crucial. In this study, the stress-strain behavior, hysteresis loss, and response characteristics for cyclic loading were analyzed through compression tests on multi-layered corrugated structure (MLCS) and expanded polystyrene (EPS) packaging materials. MLCS produced in Korea is produced by winding a certain number of single-faced corrugated paperboard, and the compression behavior of this material was turned out to be 6 stages: elastic stage, first buckling stage, sub-buckling stage, densification stage, last buckling stage and high densification stage. On the other hand, EPS's compression behavior was in 3 stages: linear elastic stage, collapse plateau, and densification stage. The strain energy per unit volume (strain energy density) of MLCS did not differ depending on the material thickness, but it showed a clear difference depending on the raw material and flute type. Hysteresis loss of MLCS ranged from 0.90 to 0.93, and there were no significant differences in the raw material and flute type. These values were about 5 to 20% greater than the hysteresis of the EPS (about 0.78 to 0.87).

• Applied Biological Chemistry
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• v.40 no.3
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• pp.225-231
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• 1997

Optimization theory was applied to a native and two imported soybeans. Failure stress and stress relaxation curve was measured with rheometer, and color was measured by colorimeter. The effects of each soybean upon the tofu texture were expressed through a non-linear canonical regression model and trace plot. Compared to the other imported soybeans, native soybean produced a higher strength in tofu texture, and showed the positive increase in viscoelastic properties such as instantaneous stress, equilibrium stress and relaxation time, whereas it had no effect on whiteness from reference blend, represented that native soy-bean showed the individual strength upon the selected rheological texture properties. Higher soaking ability in native soybean was selected as a new response for the optimization mixture process, and it contributed positively to the rheological properties of tofu. New soaking process control system during processing and desirability for the mathematical model should be applied for a better mixture design in varieties of soybeans.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.4
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• pp.299-307
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• 2011

The offshore plants such as FPSO are subjected to combination loading of environmental conditions (swell, wave, wind and current). Therefore the fatigue damage is occurred in the operation time because the units encounter the environmental phenomena and the structural configurations are complicated. This paper is a research for frequency domain fatigue analysis of wide-band random loading focused on accuracy of fatigue damage estimation regarding the proposed methods. We selected ideal bi-modal spectrum. And comparison between time-domain fatigue analysis and frequency-domain fatigue analyses are conducted through the fatigue damage ratio. Fatigue damage ratios according to Vanmarcke's bandwidth parameter are founded for wide-band. Considering safety, we recommend that Jiao-Moan and Tovo-Benasciutti methods are optimal way at the fatigue design for wide-band response. But, it is important that these methods based on frequency-domain unstably change the accuracy according to the material parameter of S-N curve. This study will be background and guidance for the new frequency-domain fatigue analysis development in the future.

• Journal of Chest Surgery
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• v.24 no.7
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• pp.637-646
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• 1991

Effect of noradrenaline and endothelium on the high K+ or Ach-induced contraction were investigated in the pig myocardial coronary artery. The helical strip of isolated pig myocardial coronary artery was immersed in the Tris-buffered Tyrode`s solution equilibrated with 100% O2 at 37oC and its isometric tension was measured. High K+ and Ach-induced contraction were dose-dependent. By denuding the endothelium, dose-contraction curve of K+ was not shifted significantly to the left and upward, but that of Ach was shifted significantly to same direction 25 mM K+ - and Ach-induced contraction were relaxed by norepinephrine[NE]. NE-induced relaxation was blocked by the pretreatment of propranolol, which was known as b-adrenoceptor blocker. And, phenylephrine known as a-adrenoceptor agonist, and clonidine known as a-adrenoceptor agonist increased the 25mM K+ - induced contraction respectively. Denuding of endothelium did not show any significant effects on NE-induced relaxation and contraction increased by phenylephrine and clonidine. Tyramine increased 25mM K+ - induced contraction further. The contractile response by tyramine on the 25mM K+ - induced contraction was not blocked by the pretreatment of phentolamine, but was partially blocked by the pretreatment of atropine. From the above results, it is suggested that activation of a1-and a2-adrenoceptors induce the contraction, activation of b-adrenoceptors induce the relaxation, and NE-induced relaxation is mainly due to activation of b-adrenoceptors. Also it is suggested that denudation of endothelium did not influence NE-induced relaxation, but influence Ach-induced contraction in the pig myocardial coronary artery.

• Journal of Korea Water Resources Association
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• v.47 no.3
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• pp.269-283
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• 2014

This study evaluated the environmental impact based on watershed characteristics and climate change using RCP climate change scenarios provided by the Korea Meteorological Administration. Future dam inflow was estimated by the SWAT model. Dam safety evaluation and downstream duration curve analysis was performed using HEC-ResSim model. Trends of water quality was analyzed through seasonal-Kendall Test using existing water quality observation data. Release discharge and tributary runoff derived SWAT and HEC-ResSim models applied to Qual2E and the future change in water quality trends were analyzed. Integrated environmental review watershed following techniques will be able to obtain the river environment management system and environmental issues such as climate change, new guidelines for preemptively response will be provided.