• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.416-417
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• 1999

• Proceedings of the Korean Magnestics Society Conference
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• 2012.11a
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• pp.140-142
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• 2012

• Journal of Sensor Science and Technology
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• v.20 no.4
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• pp.266-271
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• 2011

A reflection-type fiber-optic pH sensor, which is composed of a pH sol-gel film, plastic optical fibers, a mirror, a light source and a spectrometer, is developed in this study. As pH indicators, a bromthymol blue, a cresol red and a thymol blue are used, and they are immobilized in the sol-gel films. The emitted light from a light source is guided by a fiber-optic Y-coupler and plastic optical fibers to the pH sol-gel film in a pH sensing probe. The pH change in the sensing probe gives rise to a change in the color of the pH sol-gel film, and the optical characteristic of reflected light through the pH sol-gel film is also changed. Therefore, we have measured the spectra of reflected lights, which are changed according to the color variations of the pH sol-gel films with different pH values, by using of a spectrometer. Also, the relationships between the pH values and the intensities of reflected lights are obtained on the basis of the color variations of the pH sol-gel films.

• Journal of Sensor Science and Technology
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• v.16 no.1
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• pp.33-38
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• 2007

In this study, one-dimensional fiber-optic radiation sensor with an organic scintillator tip is fabricated to measure high energy X-ray beam profile of CLINAC. According to the energy and field size of X-ray, scintillating light signal from one-dimensional fiber-optic sensor is measured using a photodiode-amplifier system. This sensor has many advantages such as high resolution, real-time measurement and ease calibration over conventional ion chamber and film.

• BMB Reports
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• v.55 no.7
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• pp.323-335
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• 2022

Together with neuronal loss, the existence of insoluble inclusions of alpha-synuclein (α-syn) in the brain is widely accepted as a hallmark of synucleinopathies including Parkinson's disease (PD), multiple system atrophy, and dementia with Lewy body. Because the α-syn aggregates are deeply involved in the pathogenesis, there have been many attempts to demonstrate the mechanism of the aggregation and its potential causative factors including post-translational modifications (PTMs). Although no concrete conclusions have been made based on the previous study results, growing evidence suggests that modifications such as phosphorylation and ubiquitination can alter α-syn characteristics to have certain effects on the aggregation process in PD; either facilitating or inhibiting fibrillization. In the present work, we reviewed studies showing the significant impacts of PTMs on α-syn aggregation. Furthermore, the PTMs modulating α-syn aggregation-induced cell death have been discussed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.7
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• pp.1009-1013
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• 2013

In this study, we developed a fiber-optic goniometer for the continuous measurement of knee joint angle which provides important medical information on Alzheimer's disease. The fiber-optic goniometer is composed of a light-emitting diode (LED), a plastic optical fiber (POF), and a voltage output photodiode (PD). As a sensing part of the fiber-optic goniometer, a unclad fiber with regular intervals of 1 mm was fabricated to improve efficiency of bending loss according to the angle variation of knee joint. The emitting light with a center wavelength of 470 nm from a LED is guided by a POF to the PD, the transmitted light is then attenuated by the bending loss inside the bent POF. The intensity variation of the light transmitted from the POF gives rise to a change in output voltage in the fiber-optic goniometer. Therefore, we measured the real-time output voltage of the proposed fiber-optic goniometer using the unclad fiber according to the knee joint angle. Through the repeated experiments, the fiber-optic goniometer shows that it has a reversibility and a wide measurable angle range.

• Journal of Biomedical Engineering Research
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• v.27 no.5
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• pp.260-266
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• 2006

Due to damaged vertebrae nerves, serious disease and aging, patients who have to lie down for long period of time need to exercise to maintain up-right standing position and recover their paralytic leg. This study describes a development of an intellectual tilt table which can provide a patient with rehabilitating condition. This can be possible by measuring and displaying the hee bent angle and pressure for each foot during exercise in real time. It is expected that the patient's exercising effect can increase by monitoring these two values during exercise.

• Journal of the Ergonomics Society of Korea
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• v.29 no.2
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• pp.197-202
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• 2010

The purpose of this study was to examine differences between male and female in heart rate due to 93% oxygen administration of the three levels (1L/min, 3L/min, and 5L/min). Ten healthy male (25.0$\pm$1.8years) and ten female (23.7$\pm$1.9years) college students were selected as the subjects for this study. The experiment consisted of three runs, i.e., the three levels of 93% oxygen administration, respectively. The each run consisted of three phases, i.e., Rest 1 (5min), Hyperoxia (10min), and Rest 2 (5min). Heart rate was measured throughout the three phases. Heart rate was decreased during hyperoxia compared to Rest 1 and 2. By increasing the supply rate of highly concentrated oxygen, ${\Delta}1$ (decreasing rate of heart rate during hyperoxia compared to Rest 1) was increased. And ${\Delta}2$ (decreasing rate of heart rate during hyperoxia compared to Rest 2) of male was lower than female, regardless of supply rate.

• Biomedical Science Letters
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• v.22 no.4
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• pp.127-139
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• 2016

A species of the fungal genus Cordyceps has been used as an ingredient of traditional Chinese medicine. In this study, we prepared cordycepin-enriched WIB-801CE, an ethanol extract from culture solution of Cordyceps militaris-hypha, and evaluated its antiplatelet effects on human platelet aggregation. WIB-801CE dose-dependently inhibited ADP-, collagen-, and thrombin-induced platelet aggregation. These antiplatelet effects by WIB-801CE were associated with the attenuation of thromboxane $A_2$ ($TXA_2$) production and serotonin release by ADP, collagen, and thrombin. The inhibition of $TXA_2$ production by WIB-801CE was due to the inhibition of cyclooxygenase-1, $TXA_2$ synthase, and cytosolic phospholipase $A_2$ activity. Therefore, these data suggest that WIB-801CE may be a beneficial component against protection from platelet aggregation-mediated thrombotic disease.

• Biomedical Science Letters
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• v.10 no.1
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• pp.9-13
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• 2004

We have investigated the effects of hypha-water extracts (HWE), fruit body-water extracts (FWE) and cordycepin from Cordyceps militaris on serotonin release out of human platelets and human platelet aggregation. HWE and FWE inhibited the release of [$^3H$]-serotonin from human platelet stimulated by thrombin (2 U/ml) or collagen (20$\mu$g/ml) in a dose-dependent manner. Furthermore, cordycepin, a major component of Cordyceps militaris, inhibited the human platelet aggregation induced by collagen (10$\mu$g/ml) in a dose-dependent manner. These results suggest that cordycepin containing in HWE and FWE may inhibit the serotonin release by suppressing the collagen-induced human platelet aggregation. Accordingly, our data demonstrate that HWE and FWE containing much cordycepin might have antithrombotic and antimigrainous functions.