• International Journal of Oral Biology
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• v.40 no.2
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• pp.63-69
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• 2015

Curcumin (diferuloylmethane), a constituent of turmeric powder derived from the rhizome of Curcuma longa, has been shown to inhibit the growth of various types of cancer cells by regulating cell proliferation and apoptosis. However, a need exists to design more effective analogs because of curcumin's poor intestinal absorption. EF-24 (diphenyl difluoroketone), the monoketone analog of curcumin, has shown good efficacy in anticancer screens. However, the effects of curcumin and EF-24 on salivary gland epidermoid carcinoma cells are not clearly established. The main goal of this study was to investigate the effects of curcumin and EF-24 on cell growth and induction of apoptosis in human salivary gland epidermoid carcinoma cells. Our studies showed that curcumin and EF-24 inhibited the growth of HTB-41 cells in a dose- and time-dependent manner, and the potency of EF-24 was > 34-fold that of curcumin. Treatment with curcumin or EF-24 resulted in nuclear condensation and fragmentation in HTB-41 cells, whereas the control HTB-41 cell nuclei retained their normal regular and oval shape. Curcumin and EF-24 promoted proteolytic cleavages of procaspase-3/-7/-9, resulting in an increase in the amount of cleaved caspase-3/-7/-9 in the HTB-41 cells. Caspase-3 and -7 activities were detected in viable HTB-41 cells treated with curcumin or EF-24. These results suggest that the curcumin and EF-24 inhibit cell proliferation and induce apoptosis in HTB-41 human salivary gland epidermoid carcinoma cells, and that they may have potential properties as an anti-cancer drug therapy.

• Annals of Clinical Neurophysiology
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• v.13 no.2
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• pp.80-86
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• 2011

Background: A dry-type electrode is an alternative to the conventional wet-type electrode, because it can be applied without any skin preparation, such as a conductive electrolyte. However, because a dry-type electrode without electrolyte has high electrode-to-skin impedance, an impedance-converting amplifier is typically used to minimize the distortion of the bioelectric signal. In this study, we developed an active dry electroencephalography (EEG) electrode using an impedance converter, and compared its performance with a conventional Ag/AgCl EEG electrode. Methods: We developed an active dry electrode with an impedance converter using a chopper-stabilized operational amplifier. Two electrodes, a conventional Ag/AgCl electrode and our active electrode, were used to acquire EEG signals simultaneously, and the performance was tested in terms of (1) the electrode impedance, (2) raw data quality, and (3) the robustness of any artifacts. Results: The contact impedance of the developed electrode was lower than that of the Ag/AgCl electrode ($0.3{\pm}0.1$ vs. $2.7{\pm}0.7\;k{\Omega}$, respectively). The EEG signal and power spectrum were similar for both electrodes. Additionally, our electrode had a lower 60-Hz component than the Ag/AgCl electrode (16.64 vs. 24.33 dB, respectively). The change in potential of the developed electrode with a physical stimulus was lower than for the Ag/AgCl electrode ($58.7{\pm}30.6$ vs. $81.0{\pm}19.1\;{\mu}V$, respectively), and the difference was close to statistical significance (P=0.07). Conclusions: Our electrode can be used to replace Ag/AgCl electrodes, when EEG recording is emergently required, such as in emergency rooms or in intensive care units.

• Journal of the Korean Magnetics Society
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• v.15 no.6
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• pp.325-331
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• 2005

The magnetic Hut leakage (MFL) type nondestructive testing (NDT) method is widely used to detect corrosion and defects, mechanical deformation of the underground gas pipelines. The object pipeline is magnetically saturated by the magnetic system with permanent magnet and yokes. Because of the strong magnetic field enough to saturate the pipe, there could be distortion of the sensing signals because of the magnetization of the pipeline itself, To detect the defects precisely, the sensing signals are need to be compensated to eliminate the distortions coming from the media hysteresis. In this paper, the magnetizations of the pipeline in MFL type NDT are analyzed by Preisach model and 3D FEM. The distortions of the sensing signals are analyzed.

• Journal of Korea Water Resources Association
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• v.51 no.9
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• pp.803-812
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• 2018

The purpose of this study is to develop Particle Swarm Optimization (PSO) automatic calibration algorithm with multi-objective functions by Python, and to evaluate the applicability by applying the algorithm to the Soil and Water Assessment Tool (SWAT) watershed modeling. The study area is the upstream watershed of Gongdo observation station of Anseongcheon watershed ($364.8km^2$) and the daily observed streamflow data from 2000 to 2015 were used. The PSO automatic algorithm calibrated SWAT streamflow by coefficient of determination ($R^2$), root mean square error (RMSE), Nash-Sutcliffe efficiency ($NSE_Q$), and especially including $NSE_{INQ}$ (Inverse Q) for lateral, base flow calibration. The results between automatic and manual calibration showed $R^2$ of 0.64 and 0.55, RMSE of 0.59 and 0.58, $NSE_Q$ of 0.78 and 0.75, and $NSE_{INQ}$ of 0.45 and 0.09, respectively. The PSO automatic calibration algorithm showed an improvement especially the streamflow recession phase and remedied the limitation of manual calibration by including new parameter (RCHRG_DP) and considering parameters range.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.7
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• pp.744-751
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• 2010

In this paper, the design of multilayer radome within, the insertion loss, －0.3 dB in X-band with PSO was carried out based on two cases. The first is that, deciding material constant of skin and core, each layer thickness of c-sandwich radome with PSO is found and the second is that, deciding material constant and thickness of the skins of both sides, the material constant and thickness of three layers between skins of both sides using PSO is decided. The performance of the designed radome almost agreed with the required performance. It was showed that the radome design applying PSO algorithm is easy and fast and the optimum radome is also designed in combination of the various parameters of radome. From these results, the radome having various performance can be designed except the tedious calculation and also be applied to various radome structure.

• The Transactions of the Korea Information Processing Society
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• v.3 no.3
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• pp.439-448
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• 1996

Extraction and selection of the informative features play a central role in pattern recognition. This paper describes a modified back-propagation algorithm that performs selection of the informative features and trains a neural network simultaneously. The algorithm is mainly composed of three repetitive steps : training, connection pruning, and input unit elimination. Afer initial training, the connections that have small magnitude are first pruned. Any unit that has a small number of connections to the hidden units is deleted,which is equivalent to excluding the feature corresponding to that unit.If the error increases,the network is retraned,again followed by connection pruning and input unit elimination.As a result,the algorithm selects the most im-portant features in the measurement space without a transformation to another space.Also,the selected features are the most-informative ones for the classification,because feature selection is tightly coupled with the classifi-cation performance.This algorithm helps avoid measurement of redundant or less informative features,which may be expensive.Furthermore,the final network does not include redundant parameters,i.e.,weights and biases,that may cause degradation of classification performance.In applications,the algorithm preserves the most informative features and significantly reduces the dimension of the feature vectors whiout performance degradation.

• Korean Journal of Applied Biomechanics
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• v.20 no.4
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• pp.469-477
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• 2010

The purpose of this study was to evaluate the effects of insole-equipped ankle-foot-orthoses (AFO) on gait. 10 healthy males who had no history of injury in the lower extremity participated in this study as the subjects. The foot of each subject was first scanned, and the insole fit to the plantar was made using BDI-PCO(Pedcad Gmbh, Germany). The subject then was made to walk on a treadmill under four experimental conditions: 1) normal walking, 2) walking wearing AFO, 3) walking wearing AFO equipped with the insole, 4) walking wearing pneumatic-ankle-foot-orthosis (pAFO) equipped with the insole. During walking, foot pressure data such as maximum force, contacting area, peak pressure, and mean pressure was collected using Pedar-X system (Novel Gmbh, Germany) and EMG activity of lower limb muscles such as gastrocnemius medial head, gastrocnemius lateral head, and soleus was recorded using MP150 EMG module (BIOPAC System Inc., USA). Collected data was then analyzed using paired t-test in order to investigate the effects of the insole. As a result of the analysis, when insole was equipped, overall contacting area was increased while both the highest peak pressure and the mean pressure were significantly decreased, and EMG activity of the lower limb muscles was decreased. On the contrary, the cases of wearing AFO showed the decreased contacting area and the increased pressures. Therefore, the AFO equipped with a proper insole fit well to the foot can help comfortable walking by spreading the pressure over the entire plantar.

• Journal of Chest Surgery
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• v.44 no.5
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• pp.332-337
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• 2011

Background: The optimal timing of surgery for infective endocarditis complicated by embolic stroke is unclear. We compared early versus delayed surgery in these patients. Materials and Methods: Between 1992 and 2007, 56 consecutive patients underwent open cardiac surgery for the treatment of infective endocarditis complicated by acute septic embolic stroke, 34 within 2 weeks (early group) and 22 more than 2 weeks (delayed group) after the onset of stroke. Results: The mean age at time of surgery was $45.7{\pm}14.8$ years. Stroke was ischemic in 42 patients and hemorrhagic in 14. Patients in the early group were more likely to have highly mobile, large (>1 cm in diameter) vegetation and less likely to have hemorrhagic infarction than those in the delayed group. There were two (3.7%) intraoperative deaths, both in the early group and attributed to neurologic aggravation. Among the 54 survivors, 4 (7.1%), that is, 2 in each group, showed neurologic aggravation. During a median follow-up of 61.7 months (range, 0.4~170.4 months), there were 5 late deaths. Overall 5-year neurologic aggravation-free survival rates were $79.1{\pm}7.0%$ in the early group and $90.9{\pm}6.1%$ in the delayed group (p=0.113). Conclusion: Outcomes of early operation for infective endocarditis in stroke patients were similar to those of the conventional approach. Early surgical intervention may be preferable for patients at high risk of life-threatening septic embolism.

• Journal of Veterinary Clinics
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• v.31 no.6
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• pp.523-526
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• 2014

Three dogs were admitted for repair of bone fracture. Case 1 (Maltese, 1.8 kg, intact female, 5-month-old) and case 2 (poodle, 3.0 kg, intact female, 6-month-old) had non-weight bearing lameness in the left pelvic limb, and case 3 (mixed, 3.3 kg, intact female, age unknown) had non-weight-bearing lameness in the left thoracic limb. On orthopedic examination, there was pain, crepitus, palpable instability and substantial soft tissue swelling on the affected side. No neurological deficits were identified. Radiographs revealed left proximal metaphyseal tibial and fibular fractures in cases 1 and 2, and left proximal metaphyseal radial and ulnar fractures in case 3. All cases had closed long-bone fractures with short juxta-articular fracture segments. Under fluoroscopic guidance, proper placement of the ring fixation elements was confirmed during surgery. Two or three rings were used to stabilize fractures with traditional circular external skeletal fixators (CESF). Postoperative radiographs showed acceptable alignment and apposition of the previously identified fracture. Time to radiographic union ranged from 5 to 14 weeks and there were no signs of implant failure or pin tract infection. Functional outcomes were excellent in all cases. CESF can be successfully used to reduce short juxta-articular fractures in which bone plates or external skeletal fixation cannot be applied.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.1
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• pp.59-69
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• 2017

Objectives: The objective of this study is to evaluate the exposure of VOCs and effects of the chemicals on the nail technicians whose works in a nail shop. Methods: For four month from May to August in 2016, we measured twenty-two kinds of VOCs in ten nail shops and carried out health examinations on thirty-four workers in there. Results: The TVOC concentration in indoor air of nail shops is $0.487mg/m^3$ at a minimum and $33.236mg/m^3$ at a maximum where it consists of 70.5% of Ketones, 25.4% of Alcohols, 2.6% of Esters, 0.8% of Aldehydes and 0.7% of Aromatics. The VOCs concentration during nail art works shows an increase in average ratio 1.8 compared to the concentration of indoor air quality and also the concentration of Isopropanol rose with 3.2 of the highest ratio. The results of Spearman correlation between TVOC concentration in indoor air and environmental factor was like that has significance level of correlation(${\rho}$<0.05, r=0.682) in case of number of customers per day, but the other factors were not meaningful in correlation. Correlation between VOCs and medical check-up items was like that has positive significance level(${\rho}$<0.01, r=0.638) between isopropanol and GPT, but the others have not meaningful. The exposure level of VOCs was not exceed the criteria exposure level 1 of working environment measuring method which announced by labor ministry in all ten nail shop indoor air quality. Conclusions: In this study although it was not significant correlation between harmful substances and medical check-up items in the nail shop indoor air quality, it is necessary to do more ventilation and to install exhaust facilities because of existing high VOCs concentration in the nail shop indoor air.