• Journal of Ginseng Research
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• v.39 no.3
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• pp.257-264
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• 2015

Background: Korean Red Ginseng-a steamed root of Panax ginseng Meyer-has long been used as a traditional medicine in Asian countries. Its antipruritic effect was recently found, but no molecular mechanisms were revealed. Thus, the current study focused on determining the underlying molecular mechanism of Korean Red Ginseng extract (RGE) against histamine-induced itch at the peripheral sensory neuronal level. Methods: To examine the antipruritic effect of RGE, we performed in vivo scratching behavior test in mice, as well as in vitro calcium imaging and whole-cell patch clamp experiments to elucidate underlying molecular mechanisms. Results: The results of our in vivo study confirmed that RGE indeed has an antipruritic effect on histamine-induced scratching in mice. In addition, RGE showed a significant inhibitory effect on histamine-induced responses in primary cultures of mouse dorsal root ganglia, suggesting that RGE has a direct inhibitory effect on sensory neuronal level. Results of further experiments showed that RGE inhibits histamine-induced responses on cells expressing both histamine receptor subtype 1 and TRPV1 ion channel, indicating that RGE blocks the histamine receptor type 1/TRPV1 pathway in sensory neurons, which is responsible for histamine-dependent itch sensation. Conclusion: The current study found for the first time that RGE effectively blocks histamine-induced itch in peripheral sensory neurons. We believe that the current results will provide an insight on itch transmission and will be helpful in understanding how RGE exerts its antipruritic effects.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.34 no.4
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• pp.24-36
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• 2021

Objectives : This study was conducted to confirm the anti-oxidative effect of Chungpyesagan-tang(CPSGT) extract. Methods : In this study, MTT assay was performed to confirm cell viability, and DPPH and ABTS were performed to confirm radical scavenging ability. The ROS scavenging ability and the protective effect against DNA damage were confirmed by 2,7-dichlorofluorescin diacetate(DCF-DA) and 4',6-diamidino-2-phenylindole(DAPI) staining and comet assay. mRNA expression of Heme oxygenase-1(HO-1) was measured by real-time PCR, and expression of HO-1 and Kelch-like ECH-associated protein 1(Keap1) proteins was measured by western blot. Results : CPSGT was not cytotoxic at 50-400㎍/㎖. The radical scavenging activity was increased, and the ROS scavenging activity and the protective effect against DNA damage were increased compared to the LPS-treated group. The mRNA expression and protein expression of HO-1 were increased in a concentration-dependent manner. The protein expression level of Keap1 was decreased in a concentration-dependent manner. Conclusion : This suggests that CPSGT has an antioxidant effect and can be used as a potential material for skin diseases.

• Tunnel and Underground Space
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• v.14 no.1
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• pp.69-77
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• 2004

Investigation of the time-dependent behavior of rock and the associated mechanisms are of key interest in long-term stability analysis of many engineering applications. In this study, creep tests were performed on Daejeon granite samples of 25.4mm diameter under uniaxial compression at varying stress levels. The effect of moisture was investigated by testing both air-dried and fully water-saturated samples. The creep behavior of Daejeon granite exhibited three distinctive stages of primary, secondary and tertiary creep. The ultimate strength of granite under a constant stress decreased considerably with time. Saturation and immersion of the test specimen in water markedly increased the total creep strain as well as the secondary creep rate. The experimental creep curves are fitted to Burger's model as well as two other empirical models suggested by previous researchers. A number of the parameters determined for each model are dependent on stress and influenced by the presence of water. Based on the experimental results, an empirical relation between the applied stress and the time-dependent strain is established separately for each air-dried and fully water-saturated Daejeon granite.

• Korean Journal of Remote Sensing
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• v.38 no.6_4
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• pp.1879-1887
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• 2022

In this study, a method of estimating the velocity and altitude of aircrafts photographed in a KOMPSAT-3 satellite was proposed. In the proposed method, parallax effect, which is a time offset between bands due to the photographing method of the KOMPSAT-3 satellite, the structure of the sensor, and the movement of the satellite's orbit, was calculated, and in this process, trucks running on the highway were used. In addition, the actual direction and the direction by parallax effect of the aircraft were calculated using the coordinates of the aircraft in the image, and the attitude information of the KOMPSAT-3 satellite was calculated using metadata to estimate the velocity and altitude of the aircraft. The estimated value through the proposed method was compared with the actual value, automatic dependent surveillance-broadcast (ADS-B), and the error rate was calculated here. As a result, it was confirmed that the velocity and altitude error rate of large aircraft (I1, I3, S2) were lower than that of light aircraft (I2, S2), and the estimated velocity and altitude were relatively high in large aircraft using the proposed method.

• Structural Engineering and Mechanics
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• v.28 no.1
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• pp.19-38
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• 2008

A general solution to the field equations of homogeneous isotropic generalized thermoelastic diffusion with two relaxation times (Green and Lindsay theory) has been obtained using the Fourier transform. Assuming the disturbances to be harmonically time.dependent, the transformed solution is obtained in the frequency domain. The application of a time harmonic concentrated and distributed loads have been considered to show the utility of the solution obtained. The transformed components of displacement, stress, temperature distribution and chemical potential distribution are inverted numerically, using a numerical inversion technique. Effect of diffusion on the resulting expressions have been depicted graphically for Green and Lindsay (G-L) and coupled (C-T) theories of thermoelasticity.

• Journal of the Korean Society of Safety
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• v.23 no.1
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• pp.51-56
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• 2008

This study aims to investigate the effect of handle angles of pliers on performances of task completion time and the number of errors, and subjective ratings of preference. For doing this, an experiment was conducted, where 14 subjects of 11 college-age male and three female students participated. In the experiment, plier handles angled at $0^{\circ}$, $10^{\circ}$, $20^{\circ}$, $30^{\circ}$, and $40^{\circ}$ were used as independent variable, and the task completion time and the number of errors, and subjective ratings of preference as dependent variables. The subjects were instructed to do two tasks of bending an iron plate by $90^{\circ}$ and cutting wires. The results revealed that while the performances of task completion time and the number of errors were not statistically different depending upon the handle angles of pliers, the subjective ratings of preference were significantly different. Based on the results, it is recommended that the pliers with handles bent by $20^{\circ}$ be used in real situations.

• Water for future
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• v.25 no.2
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• pp.67-78
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• 1992

Several field surveys were conducted to investigate changes of water quality with time in a tidal river. Results indicated that nitrification process were dependent on the change of salinity and suspended solids concenttration. Therefore laboratory batch experiments were conducted, using suspended solids and sediment taken from a tidal river, to study the effect of salinity on nitrification and to estimate kinetic parameters of it in the tidal river. suspended solids and sediment were sampled at a point in the middle stream. Sediments were collect from the aerobic layer of mud. The change of nitrogen concentration with time was clearly explained with Monod groth model and kinetic parameters were obtained by curve fitting method. Changes in NH4-N, NO2-N, and NO3-N concentrations in the river ROKKAU with time were simulated well using Lagrangian reference frame and parameter values obtained in the laboratory tests. T도 mechanism of nitrification by suspended solids and sediment in a tidal river is shown to depend on tidal effects.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.676-681
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• 2001

In this paper, the spin-up from rest to a state of solid-body rotation in a circular container with a slender rectangular obstacle on the bottom wall is analysed experimentally. We use a PIV method for the evolution of the free-surface flow. Laboratory experiments have been carried out for a variety of the obstacle height h(0, 5, 10 [mm]) and the liquid depth H(25, 50, 75, 100 [mm]). It was found that the spin-up time is crucially dependent on the obstacle height T. In the case of T=10[mm] the spin-up time is considerably shorter then the other cases.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.517-521
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• 2001

Measurement techniques for the in-duct source characteristics of fluid machines can be classified into direct method and load method, according to whether the technique employs an external acoustic source or not. It has been known that the two methods yield different results and the load method used to come up with a negative source resistance, in spite of the fact that a very accurate prediction of radiated noise can be obtained by using any result. This paper is focused to the effect of time-varying nature of fluid machines on the output result. For this purpose, a simplified fluid machine consisting of a reservoir, a valve and a pipe is considered as representing a typical linear, periodic, time-varying system and the measurement techniques are simulated by utilizing the Hill equation and its steady-state forced response. In the load method, the source impedance turns out being dependent on the valve impedance at the calculation frequency and the valve and load impedances at other frequencies as well.

• Journal of Korean Society for Quality Management
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• v.47 no.3
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• pp.571-582
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• 2019

Purpose: To develop a risk metric for failure cause that can help determine the action priority of each failure cause in FMEA considering time sequence of cause- failure- detection. Methods: Assuming a quadratic loss function the unfulfilled mission period, a risk metric is obtained by deriving the failure time distribution. Results: The proposed risk metric has some reasonable properties for evaluating risk accompanied with a failure cause. Conclusion: The study may be applied to determining action priorities among all the failure causes in the FMEA sheet, requiring further studies for general situation of failure process.