• Journal of Nutrition and Health
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• v.19 no.5
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• pp.333-341
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• 1986

Several aspects including physical development, reflex acquistion, neuromotor development and learning behavior at Y water maze were compared at the progeny of rats fed low 91.2mg/kg diet) or adequate leves(22mg/kg diet 0 of pyridoxine during growth, gestation, lactation, and adult period. Physical development and development of reflexes (righting reflex, cliff avoidance, negative geotaxis, palmar grasp, and startle reflex to sound) appeared different between control and deficient groups but not significantly. At the 2nd week, rats spent more time in supported standing during 6 minute period was longer in the control then the deficient groups. In the Y-water maze position reversal test, learning ability as judged by the number of errors was not different among three groups, but the rats in supplemented group(DC) reached the escape platform in significantly shorter time than the other two groups, which may suggest their emotional instability. In the visual discrimination test, the performance of rats from the supplemented group had the lower errors than the other groups on the early test days. but as the testing period progressed, the performance of rats in the supplemented group became inferior to those of the control and deficient groups. The performance of control group became superior to that of the deficient group.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.5
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• pp.373-380
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• 2001

The action of opioid on the hyperpolarization-activated cation current $(I_h)$ in substantia gelatinosa neurons were investigated by using whole-cell voltage-clamp recording in rat spinal brain slices. Hyperpolarizing voltage steps revealed slowly activating currents in a subgroup of neurons. The half-maximal activation and the reversal potential of the current were compatible to neuronal $I_h.$ DAMGO $(1\;{\mu}M),$ a selective- opioid agonist, reduced the amplitude of $I_h$ reversibly. This reduction was dose-dependent and was blocked by CTOP $(2\;{\mu}M),$ a selective ${\mu}-opioid$ antagonist. DAMGO shifted the voltage dependence of activation to more hyperpolarized potential. Cesium (1 mM) or ZD 7288 $(100\;{\mu}M)$ blocked $I_h$ and the currents inhibited by cesium, ZD 7288 and DAMGO shared a similar time and voltage dependence. These results suggest that activation of ${\mu}-opioid$ receptor by DAMGO can inhibit $I_h$ in a subgroup of rat substantia gelatinosa neurons.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.63-66
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• 1998

Prototype MFSFET′s using ferroelectric oxide LiNbO$_3$ as a gate insulator have been successfully fabricated with the help of 2 sheets of metal masks and demonstrated nonvolatile memory operations of the MFSFET′s. The estimated field-effect electron mobility and transconductance on a linear region of the fabricated FET were 600 $\textrm{cm}^2$/V.s and 0.16 mS/mm, respectively. The drain current of the "on" state was more than 4 orders of magnitude larger than the "off" state current at the same "read" gate voltage of 0.5 V, which means the memory operation of the MFSFET. A write voltage as low as $\pm$3 V, which is applicable to low power integrate circuits, was used for polarization reversal.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.25-28
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• 1999

Metal ferroelectric semiconductor Field Effect- Transistors(MFSFET) with various gate electrodes, that are aluminum, platinum and poly -Si, using LiNbO$_3$/Si(100) structures were fabricated and the properties of the FETs have been discussed. The drain current of the state of FET with Pt electrode was more than 3 orders of magnitude larger than the state current at the same gate voltage of 1.5 V, 7.rich means the memory operation of the MFSFET. A write voltage as low as about $\pm$4 V, which is applicable to low power integrated circuits, was used for polarization reversal. The retention properties of the FET using Al electrode were quite good up to about 10$^3$s and using Pt electrode remained almost the same value of its initial value over 2 days at room temperature.

• Journal of Magnetics
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• v.18 no.3
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• pp.235-239
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• 2013

The effect of Dy addition on the microstructure and magnetic properties of the sintered NdFeB magnets was investigated. The results of the microstructure analysis showed that Dy-free and Dy-doped samples are composed of $Nd_2Fe_{14}B$ (P42/mnm) and a trace of Nd-rich phase. Dy addition reduces significantly the pole density factor of (004), (006) and (008) crystal faces as estimated by the Horta formula. Accordingly, the coercivity of the Dy-doped sample increases from 2038 $kA{\cdot}m^{-1}$ up to 2288 $kA{\cdot}m^{-1}$. The $H_{cj}(T)/M_s(T)$ versus $H^{min}_N/M_s(T)$ (Kronm$\ddot{u}$ller-plot) behavior shows that the nucleation is the dominating mechanism for the magnetization reversal in these two kinds of magnets, and two microstructural parameters of ${\alpha}_k$ and $N_{eff}$ are obtained. The Kronm$\ddot{u}$ller-Plot gives evidence for an increase of the ${\alpha}_k$ responsible for an increase of the coercivity as the result of the increase of the magnetic field as the magnetic domain reversed.

• Nuclear Engineering and Technology
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• v.51 no.6
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• pp.1532-1539
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• 2019

This paper analyzes a new method for reducing boiling water reactor fuel temperature during a Loss of Coolant Accident (LOCA). The method uses a device called Reverse Flow Restriction Device (RFRD) at the inlet of fuel bundles in the core to prevent coolant loss from the bundle inlet due to the reverse flow after a large break in the recirculation loop. The device allows for flow in the forward direction which occurs during normal operation, while after the break, the RFRD device changes its status to prevent reverse flow. In this paper, a detailed simulation of LOCA has been carried out using the U.S. NRC's TRACE code to investigate the effect of RFRD on the flow rate as well as peak clad temperature of BWR fuel bundles during three different LOCA scenarios: small break LOCA (25% LOCA), large break LOCA (100% LOCA), and double-ended guillotine break (200% LOCA). The results demonstrated that the device could substantially block flow reversal in fuel bundles during LOCA, allowing for coolant to remain in the core during the coolant blowdown phase. The device can retain additional cooling water after activating the emergency systems, which maintains the peak clad temperature at lower levels. Moreover, the RFRD achieved the reflood phase (when the saturation temperature of the clad is restored) earlier than without the RFRD.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.32 no.2
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• pp.51-62
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• 2021

Objectives: Tic disorder is a neurodevelopmental disorder characterized by multiple involuntary movements of muscles or vocalization. Although tic symptoms subside as the patient ages, some patients suffer from significant functional impairments related to severe tic symptoms. This manuscript aimed to review the latest scientific evidences for the effect of cognitive-behavioral interventions on tic disorder. Methods: The relevant studies were identified by searching medical research databases. We focused our search on studies published between 2000 and 2020 in order to reflect the latest scientific evidence. A total of 821 articles were identified in the initial database search and 27 articles were finally included for the review after the exclusion of duplicated and irrelevant articles. Results: Behavioral therapies including habit reversal training, Comprehensive Behavioral Intervention for Tics, and exposure and response prevention were the most widely studied interventions for tic disorder and are recommended as first-line treatments for tic disorders with high confidence. Cognitive psychophysiologic approaches were also reported to be effective. Conclusion: Further studies are needed to support the future treatment of tics with low-cost and more widely available treatments, in order to ensure better treatment outcomes.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.33 no.4
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• pp.91-98
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• 2022

Objectives: Comprehensive behavioral intervention for tics (CBIT) is effective in children with chronic tic disorders. This study aimed to assess the effect of group-based CBIT (group-CBIT) on tic severity and comorbid symptoms. We compared the efficacy of group CBIT with that of a control. Methods: Thirty children with chronic tic disorder or Tourette's disorder were enrolled in this study. Eighteen were assigned to the group-CBIT for eight sessions, and 12 were assigned to the control group. Tics and comorbid symptoms were assessed pre- and post-intervention using the Yale Global Tic Severity Scale (YGTSS), Premonitory Urge for Tics Scale, attention-deficit hyperactivity disorder Rating Scale-IV, Children's Yale-Brown Obsessive-Compulsive Scale, and the Korean-Children Behavioral Checklist. We compared the pre- and post-intervention results of each group and determined the difference in the pre- and post-intervention results between intervention and the control group. Results: The YGTSS motor and vocal tic interference, global impairment, and global severity scores decreased in the intervention group only. Group CBIT was superior in reducing the motor tic interference, impairment score, and global severity score to the control group. Conclusion: The group-CBIT showed an improvement in tic symptoms, especially in reducing the level of interference and impairment of tics.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.5
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• pp.509-517
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• 2008

DNA damage accumulates in cells as a result of exposure to exogenous agents such as benzopyrene, cigarette smoke, ultraviolet light, X-ray, and endogenous chemicals including reactive oxygen species produced from normal metabolic byproducts. DNA damage can also occur during aberrant DNA processing reactions such as DNA replication, recombination, and repair. The major of DNA damage affects the primary structure of the double helix; that is, the bases are chemically modified. These modification can disrupt the molecules'regular helical structure by introducing non-native chemical bonds or bulky adducts that do not fit in the standard double helix. DNA repair genes and proteins scan the global genome to detect and remove DNA damage and damage to single nucleotides. Direct reversal of DNA damage, base excision repair, double strand break. DNA repair are known relevant DNA repair mechanisms. Four different mechanisms are distinguished within excision repair: direct reversal, base excision repair, nucleotide excision repair, and mismatch repair. Genetic variation in DNA repair genes can modulate DNA repair capacity and alter cancer risk. The instability of a cell to properly regulate its proliferation in the presence of DNA damage increase risk of gene mutation and carcinogenesis. This article aimed to review mechanism of excision repair and to understand the relationship between genetic variation of excision repair genes and head and neck cancer.

• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.595-602
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• 2006

An experimental study was conducted to investigate seismic behaviour of post-tensioned(PT) exterior slab-column connections used for the purpose to resist gravity loads only. For these, 2/3-scale, two PT post-tensioned exterior connections with two different tendon arrangement patterns and one conventional reinforced concrete(RC) exterior connection was tested under quasi-static, uni-directional reversed cyclic loading. During the lateral testing, gravity forces transferred to the column were kept constant to closely simulate a moment to shear ratio of a real building. One of the objectives of this study was to assess the necessity and/or the quantity of bottom bonded reinforcement needed to resist moment reversal which would occur under significant inelastic deformations of the adjacent lateral force resisting systems. The ACI 318 and 352 provisions for structural integrity were applied to provide the bottom reinforcement passing through the column for the specimens. Prior test results were also collected to conduct comparative studies for some design parameters such as the tendon arrangement pattern, the effect of post-tensioning forces and the use of bottom bonded reinforcement. Consequently, the impact of tendon arrangement on the seismic performance of the PT connection, that is lateral drift capacity and ductility, dissipated energy and failure mechanism, was considerable. Moreover, test results showed that the amount of bottom reinforcement specified by ACI 352. 1R-89 was sufficient for resisting positive moments arising from moment reversal under reversed cyclic loads. Shear strength of the tested specimens was more accurately predicted by the shear strength equation(ACI 318) considering the average compressive stress over the concrete($f_{pc}$) due to post-tensioning forces than that without considering $f_{pc}$.