• 제목/요약/키워드: attenuation factor

검색결과 246건 처리시간 0.028초

The Effects of Injinsaryung-san on Rat with Alcoholic Fatty Liver (인진사령산(茵蔯四苓散)이 흰쥐의 알콜성 지방간에 미치는 영향)

  • Kim, Bum Hoi
    • Herbal Formula Science
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    • 제26권2호
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    • pp.113-122
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    • 2018
  • Objectives : Alcoholic fatty liver is an early and reversible consequence of excessive alcohol consumption. The initial hepatocyte cell death stimulates subsequent inflammatory responses, leading to further liver injury and fibrosis. The objective of this study is to investigate the effects of Injinsaryung-san extract on the alcoholic fatty liver by chronic EtOH administration. Method : Male Sprague Dawley rats were used in this study. All animals were randomly divided into Normal group, treated with saline (n=10); EtOH group, treated with ethanol (n=10); EtOH+IS group, treated with ethanol+Injinsaryung-san extract (n=10). For oral administration of ethanol in Control and Sample group, the ethanol was dissolved in distilled water in concentrations of 25%(v/v). Throughout the experiment of 8 week, the rats were allowed free access to water and standard chow. Sample group were administrated by Injinsaryung-san extract daily for 8 weeks. Results : The levels of hepatic marker such as aspartate aminotransferase and alanine aminotransferase were altered. Histopathological changes were reduced and the expression of tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) was markedly attenuated by Injinsaryung-san extract. Conclusion : These data suggest that Injinsaryung-san extract could be effective in protecting the liver from alcoholic fatty liver. The hepatoprotective mechanisms of Injinsaryung-san may be related to attenuation of $TNF-{\alpha}$ protein, as well as to the inhibition of inflammatory response in the liver. Therefore, Injinsaryung-san can be a candidate to protect against alcoholic fatty liver.

Attenuation of Hepatic Graft-versus-host Disease in Allogeneic Recipients of MyD88-deficient Donor Bone Marrow

  • Lim, Ji-Young;Lee, Young-Kwan;Lee, Sung-Eun;Ju, Ji-Min;Park, Gyeongsin;Choi, Eun Young;Min, Chang-Ki
    • IMMUNE NETWORK
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    • 제15권3호
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    • pp.125-134
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    • 2015
  • Acute graft-versus-host-disease (GVHD) is characterized by selective damage to the liver, the skin, and the gastrointestinal tract. Following allogeneic hematopoietic stem cell transplantation, donor bone marrow (BM) cells repopulate the immune system of the recipient. We previously demonstrated that the acute intestinal GVHD (iGVHD) mortality rate was higher in MyD88-deficient BM recipients than that in the control BM recipients. In the present study, the role of MyD88 (expressed by donor BM) in the pathophysiology of hepatic GVHD (hGVHD) was examined. Unlike iGVHD, transplantation with MyD88-deficient T-cell depleted (TCD) BM attenuated hGVHD severity and was associated with low infiltration of T cells into the liver of the recipients. Moreover, GVHD hosts, transplanted with MyD88-deficient TCD BM, exhibited markedly reduced expansion of $CD11b^+Gr-1^+$ myeloidderived suppressor cells (MDSC) in the liver. Adoptive injection of the MDSC from wild type mice, but not MyD88-deficient mice, enhanced hepatic T cell infiltration in the MyD88-deficient TCD BM recipients. Pre-treatment of BM donors with LPS increased MDSC levels in the liver of allogeneic wild type BM recipients. In conclusion, hGVHD and iGVHD may occur through various mechanisms based on the presence of MyD88 in the non-T cell compartment of the allograft.

Evaluation of Focal Bone Mineral Density Using Three-dimensional Measurement of Hounsfield Units in the Proximal Humerus

  • Moon, Young Lae;Jung, Sung;Park, Sang Ha;Choi, Gwi Youn
    • Clinics in Shoulder and Elbow
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    • 제18권2호
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    • pp.86-90
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    • 2015
  • Background: Although there are several methods for evaluating bone quality, Hounsfield units (HU), a standardized computed tomography (CT) attenuation coefficient, provide a useful tool for estimating focal bone mineral density (BMD). The aim of this study is to investigate the HU for evaluating the degree of osteoporosis in greater tuberosity with regard to anchor positioning. Methods: Forty patients diagnosed as normal on shoulder CT were included and categorized according to age and gender. Axially sectioned CT images were processed to 3-dimensional models containing information about bone quality using Mimics (14.11 platform v14.1.1.1 Materialise). Three-dimensional anchors were simulated and positioned according to 6 regions of interest (ROI) in the greater tuberosity classified using Tingart's system. Mean HU of intra-anchor volumes in the 6 regions was measured. Results: A significant decrease in HU was observed with increasing age (p=0.0001) and menopause (p<0.001). A significant difference in HU was found between male and female groups with males showing the higher values (p=0.0001). HU of proximal areas of ROI was higher than those of distal areas (p<0.005). However, although mean HU of distal posterior ROI showed the lowest values, no statistically significant difference was found between anterior, middle, and posterior regions (p=0.087). Conclusions: Mean HU of ROIs provides a tool for preoperative assessment of focal BMD, which is a factor of suture anchor stability and can be used to aid decision-making regarding secure anchor positioning for rotator cuff repair. Our data support that the most secure point is the proximal regions of ROI.

A Study of Noise Radiation Characteristics by Rail Vibration Reduction (레일 진동감쇄에 의한 소음방사 특성에 관한 연구)

  • Kim, Jin-Ho;Jang, Dongdoo;Kim, Hee-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • 제16권4호
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    • pp.2844-2850
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    • 2015
  • Rolling noise caused by the contact between the train wheels and rails is the main factor of noise generated by the operation of railway, therefore the features of rail vibration and its correlations with noise radiation should be identified. In this study, noise radiation generated from vibration were predicted by utilizing FE model with boundary element method. Noise radiation generated from vibration were predicted by utilizing FE model with boundary element method, and were compared with the measured noise in order to validate the reliability of the analysis method. In addition, the features of noise radiation according to the rail attenuation were examined in the frequency domain, and the noise radiation has been reduced by approximately 3dB(A) with additional rail damping.

Numerical simulations of the vertical kink oscillations of the solar coronal loop with field aligned flows

  • Pandey, V.S.;Magara, T.;Lee, D.H.;Selwa, M.
    • The Bulletin of The Korean Astronomical Society
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    • 제36권2호
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    • pp.103.1-103.1
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    • 2011
  • Recent observations by Hinode show weakly-attenuated coronal loop oscillations in the presence of background flow (Ofman & Wang 2008, A&A, 482, L9). We study the vertical kink oscillations in solar coronal loops, considering field aligned flows inside the loops as well as surrounding the loops environment. The two dimensional numerical model of straight slab is used to explore the excitation and attenuation of the impulsively triggered fast magnetosonic standing kink waves. A full set of time dependent ideal magnetohydrodynamics equations is solved numerically taking into account the value of flow of the order of observed flows detected by SOT/Hinode. We find that relaxing the assumption of the limited flows within the loops enhances the damping rate of the fundamental mode of the standing kink waves by 2 - 3 % as compared to flow pattern which is basically localized within the loops. We further notice that extending the flow pattern beyond the loop thickness also enhances the strength of the shock associated with slow magnetoacoustic waves, recognized as an addition feature detected in the numerical simulation. The wider out-flow pattern destroys the oscillation patterns early as compared to narrower flow pattern, in other words we can say that it affects the durability of the oscillation. However, for the typical coronal loops parameters we find that the observed durability periods of the SOT/Hinode observation can be achieved with an out-flow Gaussian patterns for which half-width is not greater than factor 2.0 of the loop-half-width. explain a possible relation between electric current structure and sigmoid observed in a preflare phase.

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A Potential Efficacy of Rebamipide as Anti-gastric Cancer Drug (위암치료제로서 rebamipide의 잠재적 효능)

  • Min, Do Sik
    • Journal of Life Science
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    • 제26권10호
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    • pp.1214-1217
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    • 2016
  • Rebamipide is a mucosal-protective antiulcer drug, but its mechanism of action in gastric cancer remains elusive. CagA, a major virulence factor of Helicobacter pylori (H. pylori), is associated with the risk of gastric cancer. CagA protein is injected into gastric epithelial cells and deregulates a variety of cellular signaling molecules. CagA from H. pylori induces phospholipase D1 (PLD1) expression through NFκB activation in gastric epithelial cells, followed by invasion and proliferation of gastric epithelial cancer cells. Infection with cagA-positive H. pylori and expression of CagA enhances the binding of NFκB to the PLD1 promoter. Rebamipide abolishes H. pylori cagA-induced PLD1 expression via inhibition of binding of NFκB to the PLD1 promoter and also inhibits PLD activity. Moreover, rebamipide abolishes H. pylori CagA-induced β-catenin and the expression of a target cancer stem cell (CSC) marker gene via upregulation of miRNA-320a and -4496, followed by attenuation of self-renewal capacity of H. pylori CagA-infected gastric CSCs. In addition, rebamipide increases the chemosensitivity of CagA-expressed gastric CSCs and suppresses gastric carcinogenesis. Thus, it is speculated that rebamipide might show a potent efficacy as chemotherapeutic drug against gastric cancer cells. In this review, we summarizes recent results regarding the novel insights for the efficacy of rebamipide in gastric cancer cells.

The Distribution of TaqI RFLP in the Vitamin D Receptor Gene in Korean Vegetarian Men and its Association with Calcaneal Bone Mineral Density (한국인 채식 남성에서 비타민 D 수용체 유전자의 TaqI 다형성의 분포 및 종골의 골밀도와의 관련성)

  • Kang Byung-Yong;Kim So-Yeon;Lee Sang-Jin;Kim Hyun-Hee
    • Environmental Analysis Health and Toxicology
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    • 제21권1호
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    • pp.27-34
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    • 2006
  • Numerous studies reported the significant association between genetic polymorphisms in the vitamin D receptor (VDR) gene and various bone phenotypes such as bone mineral density (BMD) and bone quality, although conflicting results were produced. The objective of this study was to investigate the association between a TaqI RFLP in the VDR gene and calcaneal BMD in Korean vegetarian men, and its interaction with nutrition status as an environmental factor. BUA (broadband ultrasound attenuation), SOS (sound of speed) and stiffness index of the calcaneus were measured using an ultrasound bone densitometer in 266 Korean men (age: $mean{\pm}SD;\;50.9{\pm}12.0$ year), and a TaqI RFLP in the VDR gene analysed by PCR-RFLP method. In total subjects, the distribution of TT, Tt and tt genotypes occurred with frequencies of 90.8%, 8.8% and 0.4%, respectively. There were no significant associations between this polymorphism and osteopenia-osteoporosis or several bone phenotypes in our subjects irrespectively of nutrition status (P>0.05). Therefore, our results suggest that a TaqI RFLP in the vitamin D receptor gene does not contribute to the susceptibility to the calcaneal BMD in Korean men.

A study on the haromnic attenuation of the BF Converter (BF 컨버터의 고조파 감쇠에 관한 연구)

  • 최태섭;안인수;임승하;사공석진
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • 제14권4호
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    • pp.8-15
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    • 2000
  • In this paper, we realize the active PFC(Power Factor Correction) system of BF(Boost Forward) converter with PWM-PFM(Pulse Width Modulation-Pulse Frequency Modulation) control technique to control DC output voltage, to remove the noise like harmonics at output voltage, and to control the input current with sinusoidal wave synchronized by the source voltage.To achieve the desired load voltage and improved PFC, we first implement current shaping control at the inverting stage and make the converted output DC voltage with forward converter. After making the ratio of output voltage to current as 50V/1A and the duty ratio greater than 0.5. When input voltage is 30V and boost inductance is 1.1mH. we control the voltage changing rate according to the variation of load resistance using a PWM-PFM control technique. And finally we prove experimentally, we attenuated its harmonics and improved PF up to 0.96 using the current shaping technique.

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Irradiance Distribution in East Sea by Using Measured Optical Properties for Squid Jigging Vessels

  • Bae, JaeHyun;Kim, SangWoo;Park, TaeYang;Cho, HyunWoo;An, YoungDuk;Kim, SangHyun;Ra, HyunWoon;Cho, YoungSil;Koh, JaeSeok;Jung, MeeSuk
    • Journal of the Optical Society of Korea
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    • 제20권5호
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    • pp.547-556
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    • 2016
  • A fishing lamp is the instrument for attracting distributed fish to a certain place, and is the lighting system mainly used in fishery. In the inshore fishing, most fishing lamps are used for squid and hairtail jigging fishing, and the light source of the fishing lamps mainly used is metal halide with 1.5 KW in electric power consumption. We will analyze the irradiance distribution according to depth because squid is attracted towards light. To analyze irradiance distribution by such fishing lamps, data for seawater Type-II among the seawater types defined in 1976 are applied to East Sea. However, the Type-II data have limitations in analyzing precise seawater transmission characteristics, due to insufficient information on deep seawater. This paper analyzed the irradiance distribution of fishing lamps using the measurement of transmission characteristics in the seawater in East Sea up to 100 m underwater instead of Type-II data, which is not sufficient for transmission. A compensation factor was drawn between the actual measurement data and Type-II data through seawater transmission characteristics simulation.

Estimation of Hydraulic Characteristics and Prediction of Groundwater Level in the Eastern Coastal Aquifer of Jeju Island (제주도 동부 해안대수층의 수리특성 산정과 지하수위 예측)

  • Jo, Si-Beom;Jeon, Byung-Chil;Park, Eun-Gyu;Choi, Kwang-Jun;Song, Sung-Ho;Kim, Gi-Pyo
    • Journal of Environmental Science International
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    • 제23권4호
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    • pp.661-672
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    • 2014
  • Due to tidal force, it is very difficult to estimate the hydraulic parameters of high permeable aquifer near coastal area in Jeju Island. Therefore, to eliminate the impact of tidal force from groundwater level and estimate the hydraulic properties, tidal response technique has been mainly studied. In this study we have extracted 38 tidal constituents from groundwater level and harmonic constants including frequency, amplitude, and phase of each constituent using T_TIDE subroutine which is used to estimate oceanic tidal constituents, and then we have estimated hydraulic diffusivity associated with amplitude attenuation factor(that is the ratio of groundwater level amplitude to sea level amplitude for each tidal constituent) and phase lag(that is phase difference between groundwater level and sea level for each constituent). Also using harmonic constants for each constituent, we made the sinusoidal wave and then we constructed the synthesized wave which linearly combined sinusoidal wave. Finally, we could get residuals(net groundwater level) which was excluded most of tidal influences by eliminating synthesized wave from raw groundwater level. As a result of comparing statistics for synthesized level and net groundwater level, we found that the statistics for net groundwater level was more insignificant than those of synthesized wave. Moreover, in case of coastal aquifer which the impact of tidal force is even more than those of other environmental factors such as rainfall and groundwater yield, it is possible to predict groundwater level using synthesized wave and regression analysis of residuals.