• Journal of Plant Biology
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• v.35 no.2
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• pp.117-123
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• 1992

The effect of benzyladenine (BA) on lipid peroxidation and compositions of total insoluble proteins and chloroplast thylakoid protein from wheat primary leaves during senescence in the dark was studied. BA ($10^{-5}\;M$) treatment prevented conspicuously the loss of chlorophyll content and soluble and insoluble leaf protein contents in senescing wheat leaf segments during 4-day dark incubation. Under the BA treatment, especially, the level of insoluble protein was highly maintained than that of soluble protein. Also, the increase of malondialdehyde (MDA: the peroxidation product of membrane lipids) content was inhibited in the BA treated leaves. Three major polypeptide bands in quantity corresponding to 57, 26 and 12 KD molecular weight were clearly resolved with other minor bands by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) in the insoluble protein fraction. The insoluble protein profiles of the control leaves showed a remarkable decrease in the intensity of the 57 and 12 KD band except for 26 KD band in the 72 h dark incubation. This loss during dark incubation was reduced by BA treatment. More than 20 polypeptides were resolved in the chloroplast thylakoid membrane fraction with the most prominent bands which are 59 and 57 KD ($\alpha\;and\;\beta$ subunit of coupling factor: CF) and 26 KD (apoprotein of LHCP). The changes in thylakoid protein profile during 72 h dark incubation showed the rapid degradation in control, but this degradation was prevented in quantity by BA treatment. The above results suggested that BA would inhibit the peroxidation of membrane lipids, thereby preventing the loss of membrane proteins which led to the maintenance of the membrane integrity including chloroplast thylakoid.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.308-308
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• 2017

The low and unstable yield of soybean has been a major problem in Japan. Excess soil moisture conditions are one of the major factors to restrict soybean productivity. More than 80 % of soybean crops are cultivated in converted paddy fields which often have poor drainage. In central and eastern regions of Japan, the early vegetative growth of soybean tends to be restricted by the flooding damage because the early growth period is overlapped with the rainy season. Field observation shows that induced excess water stress in early vegetative stage reduces dry matter production by decreasing intercepted radiation by leaf and radiation use efficiency (RUE) (Bajgain et al., 2015). Therefore, it is necessary to evaluate the responses of soybean growth for excess water conditions to assess these effects on soybean productions. In this study, we aim to modify the soybean crop model (Sinclair et al., 2003) by adding the components of the restriction of leaf area development and RUE for adaptable to excess water conditions. This model was consist of five components, phenological model, leaf area development model, dry matter production model, plant nitrogen model and soil water balance model. The model structures and parameters were estimated from the data obtained from the field experiment in Tsukuba. The excess water effects on the leaf area development were modeled with consideration of decrease of blanch emergence and individual leaf expansion as a function of temperature and ground water level from pot experiments. The nitrogen fixation and nitrogen absorption from soil were assumed to be inhibited by excess water stress and the RUE was assumed to be decreasing according to the decline of leaf nitrogen concentration. The results of the modified model were better agreement with the field observations of the induced excess water stress in paddy field. By coupling the crop model and the ground water level model, it may be possible to assess the impact of excess water conditions for soybean production quantitatively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.817-822
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• 2017

The braking system is one of the most important components in vehicles and machines. It must exert a reliable braking force when they are brought to a halt. Generally, frictional heat is generated by converting kinetic energy into heat energy through friction. As the kinetic energy is converted into heat energy, high temperature heat is generated which affects the mechanical behavior of the braking system. Frictional heat affects the thermal expansion and friction coefficient of the brake system. If the temperature is not controlled, the brake performance will be decreased. Therefore, it is important to predict and control the heat generation of the brake. Various numerical analysis studies have been carried out to predict the frictional heat, but they assumed the existence of boundary conditions in the numerical analysis to simulate the frictional heat, because the simulation of frictional heat is difficult and time consuming. The results were based on the assumption that the frictional heat is different from the actual temperature distribution in a rotating brake system. Therefore, the reliability of the cooling effect or thermal stress using the results of these studies is insufficient. In order to overcome these limitations and establish a simulation procedure to predict the frictional heat, this study directly simulates the frictional heat generation by using a thermal-structure coupling element. In this study, we analyzed the thermo-mechanical behavior of a brake model, in order to investigate the thermal characteristics of brake systems by using the Finite Element method (FEM). This study suggests the necessity to directly simulate the frictional heating and it is hoped that it can provide the necessary information for simulations.

• Journal of Life Science
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• v.14 no.1
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• pp.131-140
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• 2004

T7 bacteriophage gp4 is the replicative DNA helicase that unwinds double-stranded DNA by utilizing dTTP hydrolysis energy. The quaternary structure of the active form of T7 helicase is a hexameric ring with a central channel. Single-stranded DNA passes through the central channel of the hexameric ring as the helicase translocates $5'\rightarrow3'$ along the single-stranded DNA. The DNA unwinding was measured by rapid kinetic methods and showed a lag before the single-stranded DNA started to accumulate exponentially. This behavior was analyzed by a kinetic stepping model for the unwinding process. The observed lag phase increased as predicted by the model with increasing double-stranded DNA length. Trap DNA added in the reaction had no effect on the amplitudes of double-stranded DNA unwound, indicating that the $\tau7$ helicase is a highly processive helicase. Global fitting of the kinetic data to the stepping model provided a kinetic step size of 10-11 bp/step with a rate of $3.7 s^{-1}$ per step. Both the mechanism of DNA unwinding and dTTP hydrolysis and the coupling between the two are unaffected by temperature from $4∼37^{\circ}C$. Thus, the kinetic stepping for dsDNA unwinding is an inherent property of tile replicative DNA helicase.

• Parasites, Hosts and Diseases
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• v.35 no.1
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• pp.55-62
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• 1997

The molecular weight 30 kDa membrane protein of Toxoplusma Sondii (Toxoplasma 30 kDa) apparently conserved in most strains of T. gondii and sera of infected hosts. The present study aimed to elucidate Toxoplasmc 30 kDa as a useful diagnotic antigen for serodiagnisis of toxoplasmosis by ELISA and for induction of protective immunity. Murine spleen cells immunized with the membrane antigen of T. gondii were fused with mouse Sp2/0-Ag 14 myeloma cells. Out of 8 clones selected, five were IgG2b, the others belonged to IgG 1 and IgG2a. The 30 kDa antigen was distributed mainly on the surface membrane of tachyzoites by indirect fluorescence method. Murine peritoneal macrophages which were activated by 30 kDa antigen produced more amounts of NO2 compared with crude antigen-treated group, however there were no significant differences in toxoplamacidal activity between the two groups. Higher specificity of Toxoplosma 30 kDa antigen was recognized for serodiagnosis of toxoplasmosis than the crude antigen. From these results, ToxopLasmo 30 kDa antigen enhances the cytotoxic effect of macrophages as well as a more reliable means for the serodiagnosis of toxoplasmosis by ELISA. Key words: Toxoplosma gondii, 30 kDa antigen (p30), mouse, serodiagnosis, macrophage, cytotoxicity.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.4
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• pp.398-405
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• 2001

The rivet joint has typical structural feature that can be initiation site for the fatigue crack due to the combination of local stress concentration around rivet hole and the moisture trapping. From a viewpoint of structural assurance, it is crucial to evaluate the size of crack around the rivet holes by appropriate nondestructive evaluation techniques. Lamb wave that is one of guided waves, offers a more efficient tool for nondestructive inspection of plates. The neural network that is considered to be the most suitable for pattern recognition has been used by researchers in NDE field to classify different types of flaws and flaw sizes. In this study, clack size evaluation around the rivet hole using the neural network based on the back-propagation algorithm has been tarried out by extracting some features from the ultrasonic Lamb wave for A12024-T3 skin panel of aircraft. Special attention was paid to reduce the coupling effect between the transducer and the specimen by extracting some features related to time md frequency component data in ultrasonic waveform. It was demonstrated clearly that features extracted from the time and frequency domain data of Lamb wave signal were very useful to determine crack size initiated from rivet hole through neural network.

• The Korean Journal of Pharmacology
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• v.32 no.2
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• pp.243-257
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• 1996

CCK and cholinergic agonist stimulate enzyme release from the pancreatic acini via G-protein-mediated activation of phospholipase C, In contrast secretin and related peptides increase the level of cAMP and activate cAMP-dependent protein kinase. Camostat, a synthetic protease inhibitor, causes pancreatic hypertrophy and hyperplasia by increasing the CCK release. In this study, the secretagogue-induced changes of intracellular proteins were examined in the dispersed pancreatic acini of rats with or without camostat treatment. Camostat(FOY-305, 200 mg/kg, p.o.) was given for 4 days twice daily and the dispersed acini were prepared at 12 bouts after last treatment. The profiles of Intracellular phosphoproteins were analyzed by two-dimensional gel electrophoresis after incubating the acini with $^{32}P$. The amylase release from the dispersed acini was measured. The pancreatic weight was increased to 126% of control, while amylase activity per mg acinar protein decreased to 41% of control, The maximum response of amylase release from dispersed acini to CCK-8 or carbachol was markedly decreased(65% or 46% of control, respectively). The group of intracellular proteins(24 kD, pI $4.5{\sim}8.5$) was increased in quantity by camostat. CCK-8 or secretin increased phosphorylation of a protein(34 kD, pI 4.7) in camostat-treated as well as control rats. CCK-8 increased tyrosine phosphoryiation in the acini of control rats. However, in camostat-treated rats, the basal level of tyrosine phosphorylation was increased and it was rather decreased by CCK-8. Secretin had no effect on the level of tyrosine phosphorylation in acini. These results indicate that both phospholipase C and adenylate cyclase induce phosphorylation of an intracellular acinar protein(34 kD, pI 4.7) and camostat treatment increases the basal level of tyrosine phosphorylation in acinar cells. And these results suggest that not only serine/threonine protein kinase but also protein tyrosine kinase/phosphatase are involved in the process of CCK receptor mediated stimulation-secrelion coupling.

• Journal of the Korean Magnetics Society
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• v.17 no.1
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• pp.22-25
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• 2007

In this research, magnetic properties of spin valve structures using IrMn layers as antiferromagnetic were studied depending on the thickness of the pinned layer. The spin valve structure was Si substrate/$SiO_2(2,000\;{\AA})/Mo(17\;{\AA})NiFe(21\;{\AA})/CoFe(28\;{\AA})/Cu(22\;{\AA})/CoFe(18\;{\AA})/IrMn(t\;{\AA})/Ta(25\;{\AA})$. Also, Mo film was deposited on Si substrates and the thermal annealing effect was analyzed. The resistivity of the Mo film was increased as an annealing temperature was increased up to $600^{\circ}C$. The variations of MR ratio were related with magnetic exchange coupling field of the spin valve structures for various IrMn pinned layer thickness up to 130 ${\AA}$. MR ratio and $H_{ex}$ of spin valves was about 9.05% and 277.5 Oe when the thickness of the IrMn pinned layer was $32.5\;{\AA}(t=32.5\;{\AA})$. It was increased to 9.65% and 337.5 Oe for $t=65\;{\AA}$. For $t=97.5\;{\AA}$, the MR ratio and Hex decreased to 8.2% and 285 Oe, and further decrease was observed up to $t=130\;{\AA}$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.1
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• pp.1-10
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• 2013

In this paper, a broadband planar monopole antenna for multi-band services is proposed. The physical size of the proposed antenna is miniaturized by folding a rectangular loop. And a resonance point in the 3.9 GHz band is reduced by a coupling phenomenon with the central part of the T-shaped patch and the folded rectangular loop. In addition, the T-shaped patch is inserted to the rectangular shaped monopole antenna due to deriving the broadband frequency characteristics. The frequency characteristic is optimized by adjusting the gap and length of the folded rectangular loops and a transverse diameter of the T-shaped patch. The antenna dimensions including the ground plane are $40{\times}60{\times}1.6mm^3$. It is fabricated on the FR-4 substrate(${\epsilon}_r$=4.4) using a microstrip line of $50{\Omega}$ for impedance matching. In the measured result, the bandwidth corresponding to the VSWR of 2:1 is 162 MHz(815~977 MHz) and 2,530 MHz(1.43~3.96 GHz). For analyzing the human effect by the proposed antenna, 1 g and 10 g averaged SARs are simulated and measured. As the simulated results, 1 g-averaged SAR is 1.044 W/kg, and 10 g-averaged SAR is 0.718 W/kg. This result are satisfied by the SAR guidelines which are 1.6 W/kg(1 g-averaged) and 2.0 W/kg(10 g-averaged).

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.3
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• pp.322-327
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• 2003

The water level of a steam generator of pressurized light water nuclear Power generator is known as a subject whose control is difficult because of a shrinking and swelling effect that is been mutually contradictory in a variation of feed water. In this paper, a neural network model selects first coordinative controller by a inappropriate gain of two PI controllers and the selected controller＇s gain is tuned by a fuzzy self-tuner. Model inputs consist of the water level, the feed water, and the stream flow. One controller of both coupling controllers whose gain is handled firstly is decided based upon above data. The proposed method can analyze patterns of signals using the characteristic of neural networks and select one controller that needs to be tuned through the observed result in this paper. If one controller between both the water level controller and the feed water controller is selected by the neural network model then a gain of the PI controller is suitably tuned by the fuzzy self-tuner. Rules of the fuzzy self-tuner drew from the pattern of input and output data. In the summary, the goal of this Paper is to select the suitable controller and tune the control gain of the selected controller suitably through such two processes.