• Title, Summary, Keyword: Activation

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Bone Morphogenetic Protein 2-induced MAPKs Activation Is Independent of the Smad1/5 Activation

  • Jun, Ji-Hae;Ryoo, Hyun-Mo;Woo, Kyung-Mi;Kim, Gwan-Shik;Baek, Jeong-Hwa
    • International Journal of Oral Biology
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    • v.34 no.2
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    • pp.115-121
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    • 2009
  • Bone morphogenetic protein (BMP) 2 is a potent osteogenic factor. Although both Smad1/5 and mitogenactivated protein kinases (MAPKs) are activated by BMP2, the hierarchical relationship between them is unclear. In this study, we examined if BMP2-stimulated MAPK activation is regulated by Smad1/5 or vice versa. When C2C12 cells were treated with BMP2, the activation of extracellular signal-regulated kinase (ERK), p38 MAPK and c-Jun-N-terminal kinase was evident within 5 min. The knockdown of both Smad1 and Smad5 by small interfering RNA did not affect the activation of these MAPKs. In addition, neither the overexpression of Smad1 nor Smad5 induced ERK activation. When ERK activation was induced by constitutively active MEK1 expression, the protein level and activation of Smad1 increased. Furthermore, the inhibition of constitutively active BMP receptor type IB-induced ERK activation significantly suppressed Smad1 activation. These results indicate that Smad1/5 activation is not necessary for BMP2-induced MAPK activation and also that ERK positively regulates Smad1 activation.

Kinetic Studies on Physical and Chemical Activation of Phenolic Resin Chars

  • Agarwal, Damyanti;Lal, Darshan;Tripathi, V.S.;Mathur, G.N.
    • Carbon letters
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    • v.4 no.3
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    • pp.126-132
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    • 2003
  • Granular Activated Carbon (GAC) has been proven to be an excellent material for many industrial applications. A systematic study has been carried out of the kinetics of physical as well as chemical activation of phenolic resin chars. Physical activation was carried out using $CO_2$ and chemical activation using KOH as activating agent. There are number of factors which influence the rate of activation. The activation temperature and residence time at HTT varied in the range $550{\sim}1000^{\circ}C$ and $\frac{1}{2}{\sim}8$ hrs respectively. Kinetic studies show that the rate of chemical activation is 10 times faster than physical activation even at much lower temperature. Above study show that the chemical activation process is suitable to prepare granular activated carbon with very high surface area i.e.$ 2895\;m^2/g$ in short duration of time i.e. 1 to 2 hrs at lower temperature i.e. $750^{\circ}C$ from phenolic resins.

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A Model for Activation Energy of Moisture Diffusion in Wood (수분확산(水分擴散)의 활성화(活性化)에너지 모델)

  • Kang, Ho-Yang
    • Journal of the Korean Wood Science and Technology
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    • v.20 no.4
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    • pp.21-30
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    • 1992
  • An activation energy equation for moisture diffusion in wood was developed with an assumption that activation energy is directly proportional to wood specific gravity. Theoretical activation energies obtained from the activation energy equation were revealed to be always lower than actual activation energies, which implies that activation energy isn't affected only by wood specific gravity. The other affecting factors are possibly anatomical structures of wood which determine a ratio of vapor diffusion to bound water diffusion in wood. For the convenience of estimating actual activation energy by using the activation energy equation, thirteen kinds of species were categorized into three groups according to their anatomical structures.

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Effect of the Timing of Oocyte Activation on Development of Rat Somatic Cell Nuclear Transfer Embryos

  • Roh, Sang-Ho
    • Reproductive and Developmental Biology
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    • v.29 no.4
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    • pp.229-234
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    • 2005
  • Methods for activation of reconstructed oocytes were examined for the production of nuclear transfer (NT) rat embryos using fetal neural stem cells as donor. Neural stem cells were isolated from Day 14.5 rat fetuses, and the oocytes for recipient cytoplasm were recovered from 4-week old Sprague Dawley rats. After enucleation and nuclear injection, the reconstructed oocytes were immediately exposed to activation medium consisting of 10 mM $SrCl_2$ for 4 h (immediate activation after injection; IAI), or cultured in vitro for $2\~3$ h before activation treatment (injection before activation; IBA). Pre-activated oocytes were also used for NT to test reprogramming potential of artificially activated oocytes. The oocytes were grouped as IIA (immediate injection after activation) and ABI (activation $2\~3$ h before injection). Following NT, the oocytes were cultured in vitro. Development of the NT embryos was monitored at 44 and 119 h after activation. The embryos in groups IAI, mA, and IIA were cleaved to the 2-cell stage at the rates of $36.6\%\;(15/41),\;39.5\%\;(17/43)\;and\;46.3\%$ (25/54), respectively. However, in the ABI group, only one embryo ($1.8\%$, 1/55) was cleaved after activation. After in vitro culture, two NT embryos from IAI group had developed to the morula stage $(4.9\%\cdot2/41)$. However, no morula or blastocyst was obtained in the other groups. These results suggest that immediate activation after injection (IAI) method may be used for the production of rat somatic cell NT embryos.

EFFECTS OF MANDIBULAR NERVE TRANSECTION ON TRIGEMINAL GANGLION NEURONS AND THE ACTIVATION OF MICROGLIAL CELLS IN THE MEDULLARY DORSAL HORN (하악신경 절삭이 삼차신경절 신경세포와 연수후각 소교세포 활성화에 미치는 영향)

  • Lim, Yo-Han;Choie, Mok-Kyun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.33 no.3
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    • pp.227-237
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    • 2007
  • Microglial cell activation is known to contribute to neuropathic pain following spinal sensory nerve injuries. In this study, I investigated its mechanisms in the case of trigeminal sensory nerve injuries by which microglial cell and p38 mitogen-activated protein kinase (p38 MAPK) activation in the medullary dorsal horn (MDH) would contribute to the facial pain hypersensitivity following mandibular nerve transection (MNT). And also investigated the changes of trigeminal ganglion neurons and ERK, p38 MAPK manifestations. Activation of microglial cells was monitored at 1, 3, 7, 14, 28 and 60 day using immunohistochemical analyses. Microglial cell activation was primarily observed in the superficial laminae of the MDH. Microglial cell activation was initiated at postoperative 1 day, maximal at 3 day, maintained until 14 day and gradually reduced and returned to the basal level by 60 days after MNT. Pain hypersensitivity was also initiated and attenuated almost in parallel with microglial cell activation pattern. To investigate the contribution of the microglial cell activation to the pain hypersensitivity, minocycline, an inhibitor of microglial cell activation by means of p38 MAPK inhibition, was administered. Minocycline dose-dependently attenuated the development of the pain hypersensitivity in parallel with inhibition of microglial cell and p38 MAPK activation following MNT. Mandibular nerve transection induced the activation of ERK, but did not p38 MAPK in the trigeminal ganglion. These results suggest that microglial cell activation in the MDH and p38 MAPK activation in the hyperactive microglial cells play an important role in the development of facial neuropathic pain following MNT. The results also suggest that ERK activation in the trigeminal ganglion contributes microglial cell activation and facial neuropathic pain.

Activation Enthalpies for Plastic Deformation

  • Chang-Hong Kim;Tai-Kyue Ree
    • Bulletin of the Korean Chemical Society
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    • v.1 no.1
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    • pp.39-44
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    • 1980
  • Activation energies for plastic deformation calculated from traditional phenomenological equations have been criticized frequently since the values are different by authors, and also by experimental conditions. The reasons of different activation enthalpies are clarified in this study. Our method for calculating activation enthalpies based on the authors' theory of plastic deformation was presented and discussed. The method was applied to various cases of alloys, the calculated activation enthalpies are listed and compared with the activation energies obtained by the traditional methods in order to show the reasonableness of our method. The physical meaning of the activation enthalpies which we found was clarified.

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Menu Structure Design using Asymmetric Spreading Activation in Mobile Phone (비대칭 활성화 확산 이론을 이용한 휴대폰 메뉴 구조 디자인)

  • Oh, Se-Eung;Myung, Ro-Hae
    • Journal of the Ergonomics Society of Korea
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    • v.28 no.1
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    • pp.1-7
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    • 2009
  • As products are getting more diverse and new products are entering the market faster, customers have trouble learning how to use them. User-oriented menu structures may solve this problem. In order to design user-oriented menu structures, spreading activation theory has been studied. The spreading activation test shows that the strong associative relationship between words has shorter response times. Based on the spreading activation test, asymmetric spreading activation was introduced and a hypothesis that in a well-designed menu structure, association between upper-low menu pairs is not affected by an activation direction was tested for this study. In this study the menu of a cellular phone (Model: SPH-w2900) was extracted, and underwent 1st spreading activation tests. Then, on each menu pair, response time differences (asymmetric transition) by accuracy and directions were analyzed to find out problems in labels and improve menu structures and vocabulary. Second spreading activation tests were conducted to check whether asymmetric transitions decreased. The results showed that response time differences (asymmetric transition) for activation directions were found to be dropped significantly. Asymmetric transitions in spreading activation presented in this study will be helpful to define user-oriented menu structures.

A Study on the Activation Energy of Maturity Function for Prediction of Concrete Strength (콘크리트 강도예측을 위한 적산온도 함수의 활성화에너지에 관한 연구)

  • 장종호;강용식;김용로;길배수;남재현;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.81-84
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    • 2002
  • Activation energy value is different according to cement, admixture and water-cement ratio also the relation of age-temperature is as non-linear as activation energy value is large. So to make accurate explanation for the effect of temperature on concrete strength development property, it is necessary to investigation for activation energy value. This study compares activation energy value recommended by Freiesleben and ASTM with activation energy value obtained by consequence of mortar examination according to ASTM C 1074-93. As the result of this study, activation energy value obtained by the study is 37.19KJ/mol, and in case of activation energy value obtained by the study explain temperature's influence about concrete strength development more accurate than activation energy value recommend by Freiesleben and ASTM.

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A Study on Activation Management Operation Department (수술부의 활성화와 운영에 관한 연구)

  • Kim, Sun-Il;Yanagisawa, Makoto
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.1 no.2
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    • pp.53-61
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    • 1996
  • The activation of operation department can be defined as man power, the space, energy and organization in the operation department. In this paper, we clarified the activation index of operation department and verified the relation between the activation index and the management index related to in patients. In addition, we studied the effect of the activation index on the construction and management of the operation department. As a result, we can find the followings. 1. The number of operation as the activation index of operation department regardless of the size of hospitals in Japan is smaller than in Korea and Taiwan. 2. Based on the study of the correlation between the activation index and the operation index connected to inpatient, it is found the activation of operation department is affected by average lengh of stay of inpatient. 3. It is found that plan of operation has been practically made on the basis of the number of beds. Howerver, the activation index of operation department should be utilized on the basis of the number of operation.

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The Analysis of Electromyography and Kinematic of Kumdo Player's Head Hitting (검도 머리치기 동작의 근전도 및 운동학적 분석)

  • Park, Jong-Rul
    • Korean Journal of Sport Biomechanics
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    • v.15 no.1
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    • pp.63-74
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    • 2005
  • J. R. PARK. The Analysis of Electrimyography and Kinematic of Kumdo Player's Head Hitting. Korean Journal of Sport Biomechanics, Vol. 15, No. 1, pp. 63-74, 2005. The purpose of this study were to describe and compare the selected electromyographical muscle activities of arm and kinematic data of kumdo player's head hitting. Using surface electrode electromyography, we evaluated muscle activity in 6 male players during head hitting motion. Surface electrodes were used to record the level of muscle activity in the carpi radialis, deltoid, triceps, biceps muscles during the player's head hitting. These signals were compared with %RVC(Reference voluntary contraction) which was normalized by IEMG(Integrated EMG). The kumdo head hitting motion was divided into two phases: back swing, down swing. we observed patterns of arm muscle activity throughout two phases of the kumdo head hiting The results can be summarized as follows: right elbow angle had decreased and left deltoid muscle's activation had higher than right deltoid muscle's activation, right carpi radialis muscle's activation had higher than left carpi radialis muscle's activation in back swing phase, knee angle had decreased and left triceps muscle's activation had higher than right triceps muscle's activation, right deltoid muscle's activation had higher than left deltoid muscle's activation, right carpi radialis muscle's activation had higher than left carpi radialis muscle's activation in down swing phase