• 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.

• Korean Journal of Optics and Photonics
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• v.18 no.4
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• pp.241-245
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• 2007

In this study, a two-dimensional fiber-optic radiation sensor has been developed using water-equivalent organic scintillators for photon beam therapy dosimetry. Two-dimensional photon beam distributions and percent depth doses(PDD) are measured according to the energies and field sizes of the photon beam. This sensor has many advantages such as high resolution, real-time measurement and ease of calibration over conventional radiation measurement devices.

• Journal of Sensor Science and Technology
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• v.16 no.5
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• pp.331-336
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• 2007

In this study, we have fabricated an infrared optical fiber based sensor which can monitor the respiration of a patient. The design of a chalcogenide optical fiber based sensor is suitable for insertion into a high electro-magnetic field environment because the sensor consists of low cost and compact mid-infrared components such as an infrared light source, a chalcogenide optical fiber and a thermopile sensor. A fiber-optic respiration sensor is capable of detecting carbon dioxide ($CO_{2}$) in exhalation of a patient using the infrared absorption characteristics of carbon gases. The modulated infrared radiation due to the presence of carbon dioxide is guided to the thermopile sensor via a chalcogenide receiving fiber. It is expected that a mid-infrared fiber-optic respiration sensor which can be developed based on the results of this study would be highly suitable for respiration measurements of a patient during the procedure of an MRI.

• Journal of Sensor Science and Technology
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• v.18 no.6
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• pp.467-474
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• 2009

In this study, we describe the feasibility of developing a fiber-optic temperature sensor using a thermochromic material such as 2,4,5-triphenylimidazole or also called Lophine. A sensor-tip is fabricated by mixing of a Lophine powder, which has a non-toxic and hydrophobic characteristics, and an epoxy resin. The temperature change in the sensor-tip gives rise to a change in the optical absorbance of the Lophine, and the transmittance of a light through the Lophine is also changed. We have measured the intensities of modulated lights due to the change of optical absorbance of the Lophine by using of a photo-multiplier tube(PMT). The relationships between the temperatures and the output voltages of PMT are determined to measure the temperature of water. The measurable temperature range of the fiber-optic sensor is from 5 to $30^{\circ}C$.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.4
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• pp.203-207
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• 2009

The purpose of this study was to examine differences between male and female in blood oxygen saturation due to 93% oxygen administration of the three levels (1L/min, 3L/min, 5L/min). Ten healthy male ($25.0{\pm}1.8$ years) and ten female ($23.7{\pm}1.9$ years) 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 (5 min), Hyperoxia (10 min), and Rest 2 (5 min). Blood oxygen saturation were measured throughout the three phases. By increasing the supply rate of highly concentrated oxygen, rising rate of blood oxygen saturation was increased. Blood oxygen saturation of female was higher than male regardless of supply rate of highly concentrated oxygen and phases.

• Journal of Sensor Science and Technology
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• v.17 no.6
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• pp.462-469
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• 2008

In this study, we have fabricated a fiber-optic radiation sensor using an organic scintillator and plastic optical fiber for brachytherapy dosimetry. Also, we have measured relative depth dose rates of Ir-192 source using a fiber-optic sensor and compared them with the results obtained using a conventional EBT film. Cerenkov lights which can be a noise in measuring scintillating light with a fiber-optic sensor are measured and eliminated by using of a background optical fiber. It is expected that a fiber-optic radiation sensor can be used in brachytherapy dosimetry due to its advantages such as a low cost, simple usage and a small volume.

• Journal of Sensor Science and Technology
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• v.18 no.5
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• pp.365-371
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• 2009

In this study, we have fabricated a fiber-optic pH sensor which is composed of a light source, plastic optical fibers and a spectrometer. As an indicator, a phenol red is used, and a pH liquid solution is prepared by mixing of phenol red and various kinds of pH buffer solutions in these experiments. The emitting light from a light source is guided by plastic optical fibers to the pH liquid solution, and the optical characteristic of a light is changed in the pH liquid solution according to its color change. Therefore, we have measured the intensities and wavelength shifts of the modulated lights, which are changed due to the color variations of phenol red at different pH values, by using of a spectrometer for spectral analysis. Also, the relationships between the pH values of liquid solutions and the optical properties of modulated light according to the change of color of phenol red are obtained.

• 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.

• 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.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.1
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• pp.9-13
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• 2011

The purpose of this study was to investigate the effects of the secondary tasks such as sending text message (STM) and searching navigation (SN) on skin conductance level (SCL) and deviation of vehicle speed during driving. The participants included 30 healthy adults; 14 males aged $25.2{\pm}0.9$ with $1.9{\pm}1.8$ years of driving experiences and 16 females aged $22.6{\pm}1.9$ with $1.2{\pm}0.8$ years of driving experiences. All subjects were instructed to keep a constant speed (80km/h or 100km/h). SCL and deviation of vehicle speed were measured during driving only and driving with secondary tasks. SCL and deviation of vehicle speed were more increased during the driving with secondary tasks than driving only. Secondary tasks increased an activation of sympathetic nerve system and decreased driving performance. However, there were no significant differences in the SCL and deviation of vehicle speed according to gender and speed.