• Korean Journal of Applied Biomechanics
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• v.17 no.3
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• pp.147-154
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• 2007

This study's purpose is to investigate the effects on leg muscle activity caused by perturbation, using a trapdoor system during the support phase of gait for healthy adults (n = 6, height $177.5{\pm}5.5cm$, weight $81.0{\pm}9.5kg$, age $30.0{\pm}3.3yrs$). The trapdoor had the functional ability of causing inversion or eversion. The release time for the trapdoor was specified for two times, 0.3 and 0.5 seconds after heel contact. While altering these variables, EMG was recorded for the leg muscles (rectus femoris, biceps femoris, vastus lateralis, tibialis anterior, gastrocnemius, soleus). The following conclusions were derived. The steptime was longer for the 0.5s eversion than 0.3s inversion condition. So in order to regain stability after the perturbation the unsupporting leg reached forward rapidly. This quick reflex can be observed through the center of pressure (COP) and its rapid change in direction. The gastrocnemius was activated throughout the total experiment. There was a low amount of activity recorded in the rectus femoris, vastus lateralis and tibialis anterior except for the condition of inversion 0.3s. For most of the conditions, the highest average EMG peak values were recorded during the condition of inversion 0.3s. The iEMG patterns were similar for the conditions of inversion 0.3s and eversion 0.3s. To cope with the rapid change in these conditions, the biceps femoris was activated. During the experiment except for the condition of normal gait, the activity of the soleus and gastrocnemius was relatively high. Therefore, to prevent injury from perturbation of the lower leg strengthening of the soleus and gastrocnemius is required. Likewise to prevent injury to the thigh strengthening for the biceps femoris.

• Korean Journal of Applied Biomechanics
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• v.23 no.2
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• pp.99-108
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• 2013

The purpose of this study was to analyze the kinematic characteristics of javelin to compare the characteristics between world elite athletes and local male athletes. The subjects selected 9 athletes out of total 13 athletes recorded more than 65 m in the preliminary and main competition participated in the 93rd National Sports Festival held in 2012. Three-Dimensional motion analysis using a system of 4 video cameras(Sony HXR-MC2000) at a sampling frequency of 60 fields/s was performed for this study. The Kwon3D 3.1 was used to obtain the three dimensional coordinates about the top, grip, end of javelin. And the kinematic factors of javelin calculated using Matlab2009a program. The resultant speed of javelin that affects directly to the record of performance showed 26.08 m/s indicated lower speed of about 2-3 m/s than world elite athletes. The release point appeared to have been made at the high of $1.79{\pm}0.07$ m of 99.8% of the height of the athletes. In terms of release angle, it was indicated average $33.0{\pm}3.81^{\circ}$ lower release angle compared to the world elite athletes. The attitude angle(up & down tilt angle, X axis) related to javelin indicated average $38.5{\pm}4.96^{\circ}$, its related attack angle average $5.5{\pm}5.11^{\circ}$, and yaw angle(sideslip, side attack angle) average $15.7{\pm}8.48^{\circ}$.

• Journal of Soil and Groundwater Environment
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• v.9 no.4
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• pp.62-73
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• 2004

The current status and problems of UST management in gas stations were reviewed, and suggestions were made for possible improvement of UST management. Regulations and programs relevant through the whole life cycle of the UST, such as construction, installation, operation, and disclosure are insufficient to prevent oil release. The UST requirements are less stringent compared to those of the U.S. and EU members. Current soil test does not seem to be practically effective in detecting soil contamination caused by oil release. The potential for subsurface contamination due to oil release from the UST is estimated from available data other than soil test results. Much higher following future directions and suggestions are made to improve current unsatisfactory UST management: Firstly, increasing the UST requirements - establishing more stringent standards for new UST facilities, and adding new regulatory requirements for existing UST facilities; secondly, replacing current soil test with the tank and piping tests; thirdly, reinforcing programs for supervising the tank construction and installation; fourthly, constructing a system in which independent gas stations can properly manage the USTs; and lastly, educating UST owners and operators, and constructing DB of UST facilities.

• Journal of Korean Society of Steel Construction
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• v.23 no.2
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• pp.229-236
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• 2011

This study was conducted to understand the characteristics of the compression behavior of steel plate-concrete(SC) structures with a width-to-thickness ratio under axial loading. SC structures are structural systems where concrete is poured into steel plates to which headed stud bolts had been attached inside. The specimens were classified according to the two width-to-thickness (W/T) ratios of 1.60 and 3.56. Through these experiments, the following conclusions could be arrived at. The fracture pattern of the specimens showed that steel plate buckling occurred between the stud lines, and that a crack occurred at the concrete spalling from the sides of the concrete before the system reached the maximum compressive strength. The maximum compressive strength of the specimens was larger than that of the existing equations (AISC 2005, ACI 318-05, and KBC 2005). With the increased W/T ratio of the specimens, the strength of the concrete core was decreased to account for the confinement effects from the steel plates.

• The Journal of Korean Obstetrics and Gynecology
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• v.18 no.1
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• pp.29-44
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• 2005

To address the ability of Herba Portulacae(HP) to induce cell death, we investigated the effect of HP on cell viability. Twenty-four hours later, loss of viability occurred following HP exposure in a dose-dependent manner. The treatment of HP, a commonly used herb formulation in Korea, Japan and China, caused a decrease in cell viability. HP also resulted in apoptotic morphology a brightly blue-fluorescent condensed nuclei by Hoechst 33258-staining, and reduction of cell volume. Our results show that 2mg/ml HP induces mitochondria membrane potential collapse. Immunoblotting data also shows that the expression of Bcl-2, antiaoptotic protein, decrease by the addition of HP. This GFP-Bax overexpression system shows that an important pro-apoptotic Bcl-2-family protein, Bax is translocated to mitochondria by the addition of 2mg/ml HP. Inerestingly, MAPK inhibitor study shows that p38 MAPK inhibitor, SB203580 inhibits HP-induced cell death and caspase-3 activation in HP-treated HeLa cells. Furthermore, HP transiently but significantly induces p38 activation. But P38 MAPK inhibitor does not have any effect on the translocation of Bax. Considering these results, HP induces apoptosis via p38 MAPK activation. But the pathway does not involve the translocation of Bax.

• Hwankyungkyoyuk
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• v.20 no.2
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• pp.54-66
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• 2007

The purpose of this study is to find identity of the elementary environmental education and inquire elements of professionalism in environmental education that elementary teachers should have. This study performed a half-structured interview in twice to the eight of elementary teachers who completed the environmental education curriculum course in a graduate school or participated in the teacher training program before. As a result, this study found that the identity of the elementary environmental education consists of the unification comprehending various subjects, the well-rounded sensitivity balancing intellectual, emotional and behavioral aspects, and the grounding in forming environmentally friendly living-habit and academic basis of environments. Moreover, this study found that the teacher training program for the specialty of the elementary environmental teachers should comprise of the following twelve components: the knowledge of overall environmental curriculum, environmental life guidance and environmental classroom management, environmental teaching skills and function, the passion and commitment about environmental education, environmental sensitivity, understanding of education studies, the values and attitude about environment, environmental behavior, understanding the relationship between environmental psychology and developing stage of child, the general education and communication/cooperation with colleagues or local community, understanding of the role as an teacher for the elementary environmental education. More importantly, it would be very crucial that the teachers themselves who are the main body of education system should recognize the their role as the professionals in order to improve the quality of education.

• Tribology and Lubricants
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• v.31 no.2
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• pp.56-61
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• 2015

In this study, we investigated the effectiveness of an ultrasonic nanocrystal surface modification (UNSM) technique on the mechanical and wear properties of tungsten carbide (WC). The UNSM technique is a newly developed surface modification technique that increases the mechanical properties of materials by severe plastic deformation. The objective of this study was to improve the wear resistance of press die made of WC by applying the UNSM technique. We observed the microstructures of the untreated and UNSM-treated specimens using a scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX) was used to investigate the chemical composition. The SEM observations showed the pore size and the number of pores decreased after the UNSM treatment. We assessed the wear behavior of both the untreated and UNSM-treated specimens using a scratch test. The test results showed that the wear resistance of the UNSM-treated specimens increased by about 46% compared with the untreated specimens. This may be attributed to increased hardness, reduced surface roughness, induced compressive residual stress, and refined grain size following the application of the UNSM technique. In addition, we found that the UNSM treatment increased the carbon concentration to 63% from 33%. We expect that implementing the findings of this study will lead to an increase in the life of press dies.

• Journal of Veterinary Clinics
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• v.34 no.1
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• pp.7-12
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• 2017

Twelve dogs weighing less than 10 kg underwent unilateral TTO to stabilize the stifle joint with cranial cruciate ligament rupture. Surgical findings, intra-operative and post-operative complications were recorded. Radiographic examinations were performed for 8 weeks following surgery. Postoperative outcome was evaluated using a visual analogue lameness scoring system. Mean preoperative PTA (the angle created by the intersection of the tibial plateau extrapolation line and the patellar tendon) was 103.8 degrees. Mean tibial wedge angle was 16.6 degrees. Mean postoperative PTA was 92.1 degrees. Intraoperatively, fracture through the caudal tibial cortex occurred in all dogs, through the distal tibial crest cortex in 2 dogs, through the lateral tibial cortex in 2 dogs and through the fibula in 1 dog. Four-week postoperative radiographs demonstrated evidence of progressive bone union at osteotomy site and complete unions were identified at 8 week in 10 dogs. All dogs were healed in 11 weeks. Most of dogs revealed weak lameness in 4 weeks and normal ambulation in 8 weeks postoperatively except for only one dog returned in 11 weeks. Despite frequent minor complication, it appears that the TTO is an alternative procedure for management of cranial cruciate ligament rupture in small breed dogs.

• The Journal of Internal Korean Medicine
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• v.30 no.1
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• pp.24-35
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• 2009

Object : In conditions of brain infarction, irreversible axon damage occurs in the central nerve system (CNS), because gliosis makes physical and mechanical barriers. If gliosis formation could be suppressed, irreversible axon damage would be reduced. This could mean that an injured CNS could be regenerated. CD81 and GFAP have close relationships to gliosis. The increase in glial cells at CNS injury gives rise to the expression of CD81 and GFAP. CD81 was postulated to play a central role in the process of CNS scar formation. Method : In this study, the author investigated the effect of the water extract of the Moutan Radicis Cortex on regulation of CD81 and GFAP expression in injured CNS cells. MTT assay was used to examine cell viability, while RT-PCR and ELISA methods were carried out to measure the expression of CD81 and GFAP in the astrocyte. Results : We observed that water extract of the Moutan Radicis Cortex increased cell viability under hypoxia induced by $CoCl_2$ and suppressed the expression of CD81 and GFAP up-regulated by hypoxia. Conclusion : These results suggest that the Moutan Redicis Cortex could promote neural regeneration as a consequence of protecting CNS cells from hypoxia and suppressing the reactive gliosis following CNS injury.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.4
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• pp.1014-1020
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• 2006

This study was intended to examine the effects of electroacupuncture(EA) and therapeutic exercise on the improvement of exercise function, BNDF, and HSP70 protein expression in an ischemic stroke model induced by MCA occlusion. Experiments were conducted for 1, 3 days, 1, 8 weeks respectively. Group I was a group of EA and therapeutic exercise; Group II was a group of therapeutic exercise; Group III was a group of EA; Group IV was a sham group of EA; Group V was a control group; and Group VI was a sham group without ischemic stroke. In each group, neurologic motor behavior test, histologic observations, BDNF, and HSP70 expression were observed and analyzed. The following results were obtained. The results of behavior test suggest that 8 weeks after ischemic stroke was induced, Group I improved in degeneration and inflammation of muscle fiber and decreased in destruction of nerve cells and cerebral infarction, indicating a similar state of muscle fiber and brain to Group VI. In immunohistochemical observations, Group I showed increase in BDNF and decrease in HSP70. Based on these results, EA and therapeutic exercise may improve muscle atrophy and change in BDNF and HSP70 expression of ischemic stroke rats and contribute to the improvement of exercise function.