• Title/Summary/Keyword: differential mechanism

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Differential expression of soybean SLTI100 gene encoding translation elongation factor 1A by abiotic stresses

  • Chung, Eun-Sook;Cho, Chang-Woo;So, Hyun-A;Yun, Bo-Hyun;Lee, Jai-Heon
    • Journal of Plant Biotechnology
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    • v.36 no.3
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    • pp.255-260
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    • 2009
  • The translation elongation factor 1A, eEF1A, catalyzes the binding of aminoacyl-tRNA to the A-site of the ribosome by a GTP-dependent mechanism. By subtractive suppression hybridization technique, we have isolated a soybean low-temperature inducible gene, SLTI100 encoding translation elongation factor 1A. Multiple sequence alignments and phylogenic analysis showed that SLTI100 and other eEF1As originated from diverse organisms are highly conserved. RNA expression of SLTI100 was specifically induced by low temperature, high salt, ABA, or drought stress. Based on the subcellular localization of the corresponding gene product fused to GFP, we were able to confirm that SLTI100-GFP was restricted to the nucleus and cytoplasm. We propose that soybean eEF1A may play an important role in translational regulation during abiotic stress responses in plants.

VATS Resection for a Posterior Mediastinal Extramedullary Hematopoietic Mass: Resection of Extramedullary Hematopoiesis (후종격동 종괴로 발견된 골수외 조혈 종괴의 비디오 흉강경 수술을 이용한 절제 1예)

  • Chang, Jee-Won;Maeng, Young-Hee
    • Journal of Chest Surgery
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    • v.43 no.5
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    • pp.542-545
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    • 2010
  • Extramedullary hematopoiesis is a common compensatory mechanism of chronic anemia, but an asymptomatic posterior mediastinal mass is rarely diagnosed as an extramedullary hematopoiesis after surgical resection. The differential from neurogenic tumors is important, but fine needle aspiration biopsy is not recommended because of the difficulty of approach and risk of bleeding. Although diagnosis and treatment can involve resection via thoracotomy, video-assisted thoracic surgery may also be a useful strategy. We performed video-assisted thoracic surgery on a 59-year-old man for posterior mediastinal extramedullary hematopoiesis, with no evidence of recurrence or related hematologic diseases.

Auto-guiding System for CQUEAN

  • Kim, Eun-Bin;Park, Won-Kee;Jeong, Hyeon-Ju;Kim, Jin-Young;Kim, Dong-Han;Kim, Han-Guen;Kuehne, John;Odoms, Peter S.;Choi, Chang-Su;Im, Myung-Shin;Pak, Soo-Jong
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.61.2-61.2
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    • 2010
  • CQUEAN (Camera for Quasars in EArly uNiverse) is an optical CCD camera system which has its own auto-guiding system. Guiding system consists of a 1k*1k CCD camera, FLI PL1001E, a flat mirror to feed the image of an off-axis field to the camera and baffle. The whole system lies on a moving arm which rotates 90 degree effectively to enlarge the field of view. A motor, IMS MDRIVE 34, and a differential decelerator, APEX AD140-050, are used for the moving mechanism. Auto-guiding is controlled by Agdr program. We had a first light from Aug. 10 to Aug 17, 2010 at McDonald Observatory, USA. In this presentation, we describe about the auto-guiding system for CQUEAN and its performance on the 2.1m telescope.

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Pyrolysis Reaction for the Treatment of Hazardous Halogenated Hydrocarbon Waste (유해 할로겐화 탄화수소 폐기물 처리를 위한 열분해 반응)

  • 조완근
    • Journal of Environmental Science International
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    • v.6 no.4
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    • pp.399-407
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    • 1997
  • The pyrolysis reactions of atomic hydrogen with chloroform were studied In a 4 cm 1.6. tubular flow reactor with low flow velocity 1518 cm/sec and a 2.6 cm 1.4. tubular flow reactor with high flow velocity (1227 cm/sec). The hydrogen atom concentration was measured by chemiluminescence titration with nitrogen dioxide, and the chloroform concentrations were determined using a gas chromatography. The chloroform conversion efficiency depended on both the chloroform flow rate and linear flow velocity, but 416 not depend on the flow rate of hydrogen atom. A computer model was employed to estimate a rate constant for the initial reaction of atomic hydrogen with chloroform. The model consisted of a scheme for chloroform-hydrogen atom reaction, Runge-Kutta 4th-order method for Integration of first-order differential equations describing the time dependence of the concentrations of various chemical species, and Rosenbrock method for optimization to match model and experimental results. The scheme for chloroform-hydrogen atom reaction Included 22 elementary reactions. The rate constant estimated using the data obtained from the 2.6 cm 1.4. reactor was to be 8.1 $\times$ $10^{-14}$ $cm^3$/molecule-sec and 3.8 $\times$ $10^{-15}$ cms/molecule-sec, and the deviations of computer model from experimental results were 9% and 12% , for the each reaction time of 0.028 sec and 0.072 sec, respectively.

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Induction of Lysozyme Gene Expression During Involution of Mouse Mammary Gland

  • Lee, M.J.;Han, O.;Back, K.;Choi, Y.J.;Baik, M.G.
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.4
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    • pp.462-466
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    • 2001
  • To understand molecular mechanisms of mouse mammary gland involution, clones were isolated by differential screening of a cDNA library. Partial sequences of a clone showed 100% identity to cDNA sequences of mouse lysozyme P gene. Northern analysis was performed to examine expression levels of lysozyme mRNA in mammary gland at several physiological states. Expression of lysozyme gene was induced at involution day 5 compared with lactating stage. High levels of lysozyme mRNA were also detected at virgin tissues. Two types of separate genes, P and M lysozyme, have been known in mouse, and we found that both lysozyme P and M genes were expressed in mammary tissues by reverse transcriptase-polymerase chain reaction. The lysozyme enzyme activity determined by lysoplate assay was also higher in involuted mammary tissues compared with lactating tissues, showing a similar trend to its mRNA levels. Lysozyme is an antimicrobial protein and involved in host defense mechanism. The increase in lysozyme gene expression may help to prevent microbial infection during mammary gland involution at which stage the residual milk in the mammary gland provides good nutritional sources for microbial growth.

Transient activation of the MAP kinase signaling pathway by the forward signaling of EphA4 in PC12 cells

  • Shin, Jong-Dae;Gu, Chang-Kyu;Kim, Ji-Eun;Park, Soo-Chul
    • BMB Reports
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    • v.41 no.6
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    • pp.479-484
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    • 2008
  • In the present study, we demonstrate that ephrin-A5 is able to induce a transient increase of MAP kinase activity in PC12 cells. However, the effects of ephrin-A5 on the MAP kinase signaling pathway are about three-fold less than that of EGF. In addition, we demonstrate that EphA4 is the only Eph member expressed in PC12 cells, and that tyrosine phosphorylation induced by ephrin-A5 treatment is consistent with the magnitude and longevity of MAP kinase activation. Experiments using the Ras dominant negative mutant N17Ras reveal that Ras plays a pivotal role in ephrin-A5-induced MAP kinase activation in PC12 cells. Importantly, we found that the EphA4 receptor is rapidly internalized by endocytosis upon engagement of ephrin-A5, leading to a subsequent reduction in the MAP kinase activation. Together, these data suggest a novel regulatory mechanism of differential Ras-MAP kinase signaling kineticsexhibited by the forward signaling of EphA4 in PC12 cells.

An Experimental Study on the Characteristics of Direct Photoelectric Charging (직접 광대전의 대전특성에 관한 실험적 연구)

  • Lee, Chang-Sun;Kim, Yong-Jin;Kim, Sang-Sao
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.6
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    • pp.753-759
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    • 2000
  • Photoelectric charging is a very efficient way of charging small particles. This method can be applied to combustion measurement, electrostatic precipitator, metal separation and control of micro-contamination. To understand the photoelectric charging mechanism, particle charging of silver by exposure to ultraviolet is investigated in this study. Average charges and charge distributions are measured at various conditions, using two differential mobility analyzers, a condensation nucleus counter, and an aerosol electrometer. The silver particles are generated in a spark discharge aerosol generator. After that process, the generated particles are charged in the photoelectric charger using low-pressure mercury lamp that emits ultraviolet having wavelength 253.7 nm. The results show that ultra-fine particles are highly charged by the photoelectric charging. The average charges linearly increase with increasing particle size and the charge distribution change with particle size. These results are discussed by comparison with previous experiments and proposed equations. It is assumed that the coefficient of electron emission probability is affected by initial charge. The results also show that the charge distribution of a particle is dependent on initial charge. Single changed particle, uncharged particle and neutralized particle are compared. The differences of charge distribution in each case increase with increasing particle size.

A Study on the Educational Meaning of Medical Records written in Shanghanjiushilun Focusing on Purgation Therapy (하법(下法)을 위주로 살펴본 『상한구십론(傷寒九十論)』 의안(醫案)의 교육적 의의 고찰)

  • Ahn, Jin-hee
    • Journal of Korean Medical classics
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    • v.31 no.2
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    • pp.105-126
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    • 2018
  • Objectives : This paper aims to study the educational meaning of Shanghanjiushilun in Shanghanlun education focusing on purgation therapy. Methods : Clinical medical records in Shanghanjiushilun associated with purgation therapy were chosen, analyzed and its educational meaning was studied. Results & Conclusions : 1. Xushuwei's clinical medical records are significant as it helps the readers think of various disease mechanisms by not omitting mistreatment of the other doctors. 2. Xushuwei's clinical medical records are significant as it helps the readers become aware of the importance of a differential diagnosis through questions and answers. 3. Xushuwei's clinical medical records are significant as it helps the readers avoid looking at one side of things through taking a comprehensive look at disease syndrome in various fields. 4. Xushuwei's clinical medical records are significant as it helps the readers escape unreasonableness by suggesting practical aspect managing the patient. 5. Xushuwei's clinical medical records are significant as it enable the readers to draw a new disease mechanism interpretation by making up for explanations of the pathogenesis quoting medical classics. 6. Consequently, in learning and teaching Shanghanlun, Xushuwei's clinical medical records have enough educational meaning as mentioned above.

A study on the modeling of a hexacopter

  • Le, Dang-Khanh;Nam, Taek-Kun
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.10
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    • pp.1023-1030
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    • 2015
  • The purpose of this paper is to present the basic mathematical modeling of a hexacopter, which could be used to develop proper methods for stabilization and trajectory control. A hexacopter consists of six rotors with three pairs of counter-rotating fixed-pitch blades. This mechanism is an under-actuated, dynamically unstable, six-degrees-of-freedom system. The whole motion of this object consists of translational and rotational motion in three dimensions, where the translational motion is created by changing the direction and magnitude of the upward propeller thrust. The hexacopter is controlled by adjusting the angular velocities of the rotors, which are spun by electric motors. It is assumed to be a rigid body; thus, the differential equation of the hexacopter dynamics can be derived from the Newton-Euler equation. The Euler-angle parametrization of the three-dimensional rotations contains singular points in the coordinate space that can cause failure of both the dynamical model and control. In order to avoid singularities, the rotations of the hexacopter are parametrized in terms of quaternions. This choice has been made considering the linearity of the quaternion formulation and their stability and efficiency. Further, control simulation of a hexacopter applying cascaded-PID control is also presented in this paper.

An Investigation of the Major Factors Relating to the Flow Fluctuation at a Natural Gas Metering Facility (천연가스 계량설비에서 발생하는 유량 헌팅 현상 원인 분석)

  • An, Seung-Hee;Her, Jae-Young;Jeong, Jong-Tae;Sin, Chang-Hun
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.158-165
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    • 2005
  • KOGAS(Korea Gas Corporation) has about a hundred of local stations to supply natural gas to the city gas companies and the power stations. As some severe flow fluctuation phenomena are observed in several governor stations, the investigation about the reasons and factors which are relating to flow fluctuation has been started. Some field surveys hav been carried out and experimental studies have been performed to find the fluctuation mechanism. As a result, it is found that the flow fluctuation is related with the length of straight pipe in front of the meter, the size of the header pipe and the variation of demand at the city gas company and the power station. Furthermore. it is also proved that both the length of the transmitter cable and the status of the coating of signal transmission cable do not affect flow fluctuation, but the measurement range of the differential pressure transmitter influences flow fluctuation. On the other hand, as the averaging the flow fluctuation is converged to less than 0.1 % in almost all of the cases, it is concluded that the quantity of flow fluctuation do not relates to metering accuracy directly.

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