• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.6
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• pp.30-39
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• 2016

An experimental study was performed to investigate flexural performance and bond characteristics of RC beams strengthened using ductile polyethylene terephthalate(PET) with low elastic modulus. Bond tests were planned and completed following CSA S806. Test variables were fiber type and fiber amount. Also, total of 8 RC beams was tested. Major test variables of the beam tests included section ductility(${\mu}=3.4$, 7.0), fiber type(CF, GF, PET) and amount of fiber strengthening. Moment-curvature analyses of the beam sections were also performed. In bond tests, the bond stress distribution as well as the maximum bond stress increased with increasing amount of PET. In case of 10 layers of PET, the effective bond length was 60 mm with the maximum and the average bond stress of 2.33 and 2.10 MPa, respectively. RC beam test results revealed that the moment capacity of the RC beams strengthened using PET 10 and 20 layers increased over the control beam with little reduction in ductility by fiber strengthening. All beams strengthened using PET resulted in ductile flexural failure without any sign of fiber debonding or fiber rupture. It was important to include the mechanical properties of adhesive in the moment-curvature analysis of PET-strengthened beam sections.

• Journal of the Korean Geotechnical Society
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• v.32 no.7
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• pp.25-34
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• 2016

Recently, in Korea, problems related with unstability of slope or sinkhole in urban area due to erosion of compacted granite soil which was used as a backfill or embankment material have been treated as important issues. Small hole might develop inside of backfill area due to erosion of not only weathered granite soil but also clay, silt, fine sand size particles when underground water flows. Once erosion starts in a soil mass, erosion rate increases gradually to cause rapid destruction. In this study, a rotating cylinder test (RCT) was performed to evaluate the hydraulic resistance characteristics of compacted weathered granite soil under various relative densities and preconsolidation pressures. Meanwhile, an image analysis method was introduced to analyze radius of irregularly eroded sample. It was found that image analysis is an effective means of minimizing the error in calculating a critical shear stress and threshold shear stress on the irregularly eroded sample. Furthermore, in general, hydraulic resistance capacity increases with the increase of relative density and preconsolidation pressure.

• Journal of the Korean Wood Science and Technology
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• v.44 no.1
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• pp.113-123
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• 2016

This study was to investigate the antifungal activity of A. holophylla essential oil against dermatophytes, such as Epidermophyton floccosum, Trichophyton mentagrophytes and Trichophyton rubrum, and to determine the potential effective compound as dermatitis treatment. To evaluate the potential antifungal activities of A. holophylla essential oil and its fractions, paper disc diffusion and agar dilution method tested with morphological observation. Also, their major constituents were analyzed by GC/MS. To determine synergic effects of active ingredient from A. holophylla essential oil were carried out by checkerboard microtiter plate testing. The morphological changes of the dermatophytes exposed to active fraction G4 were observed by electron microscopes. As the results, the highest activities were identified in the fraction containing ${\alpha}$-bisabolol. A mixture of ${\alpha}$-bisabolol and bornyl acetate showed the synergy effects, expressing high potential effects. Also, morphological observation using electron microscopes showed a dramatic changes of cell membrane of E. floccosum and T. rubrum exposed to fraction G4 containing ${\alpha}$-bisabolol. In conclusion, A. holophylla essential oil and its constituents were expected to be used as antifungal agent or raw material for dermatitis therapy.

• Archives of design research
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• v.13 no.3
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• pp.211-220
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• 2000

Cultural contact, which means a current that an influential culture diffuses to another, represents the penetration of the one to the other in a negative respect and'mixture'or 'fusion'of them in an affirmative respect. Fusion of cultures was not easy to take place in the past when nationalism and ultranationalism suppressed it ideologically, inconvenient transportation and communications were obstacles to it, and most of countries were under the influences of folk religions. Today, however, mutually heterogeneous cultures can be shared by a lot of things such as collapse of a view of nation resulted from globalization, breakdown of regional characteristics, abolition of trade barriers, freedom of communications and realtime information network. Those have rendered fusion possible. Fusion in this modern consuming society is extending much faster and more extensively than at any time in the past. In addition, more and more cultural elements seem to collide and compromise with one another in the name of fusion, not relaxing the bridle of fusion, from the present situations that preference in consumption becomes subdivided and a variety of individuality is strongly attempted to seek for, This study is on the subject of the properties of'Fusion', one of new styles in a mass culture, especially focused on sociologic cultural phenomena. Furthermore, it is expected to look for a fusion in interior design which expresses sociologic cultural phenomena most in a field of design, to examine it theoretically, and to prospect a future trend of fusion design based on investigation of the latest prevailing trend.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.2
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• pp.275-280
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• 2009

Radicular cyst is a true epithelium lined cyst formed when epithelium at the apex of a nonvital tooth is stimulated by inflammation. It is the most common type of cyst in the oral cavity, but its frequency is low in the primary dentition. Treatment of large-sized cyst aims at conservation of adjacent structure and allowance of proper eruption of the successive permanent teeth in the primary dentition. Considering these two aspects, marsupialization or enucleation following decompression is recommended as a treatment means for large-sized radicular cyst. In this case, 8-year old boy visited the pediatric dentistry department. Yonsei University Dental Hospital, with the chief complaint of pain on the lower right area. Clinical and radiographic examinations revealed periapical radiolucent lesion on #84, which had previous pulp treatment and restorated with the stainless steel crown. Dislocation of its successive tooth, #44, was also observed. #84 was extracted and sent for biopsy. Through histologic examination, it was diagnosed as radicular cyst. Following its extraction, removable space maintainer was delivered, which was also used as a decompressor. During periodic check-up for next 22 months, favorable healing of the lesion and eruption of the successive tooth were observed.

• Journal of Chest Surgery
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• v.29 no.8
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• pp.807-815
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• 1996

The protective effect of'ischemic preconditioning'on ischemid-reperfusion injury of heart has been reported in various animal species. but without known mechAnism in detail, In An attempt to investigate the cardioprotective mechanism of ischemic preconditioning, we examined the effects of nitric oxide(UO) synthesis in preconditioned heart of rat The isolated hearts perfused by Langendorfr's method were ex- posed to 30min global ischemia followed by 30min reperfusion with oxygenated Krebs-Henseleit(K-H) sol- ution. Ischemic preconditioning was performed with three episodes of Sm n ischemia and Smin repeyfusion before the induction of prolong ischemia(30min)-reperfusion(30min). Ischemic preconditioning prevented the depression of cardiac function(left ventricular pressure .K heart rate) observed in the ischemia- reperfusion hearts and reduced the release of lactate dehydrogenase during the reperfusion period. On electromicroscopic pictures, myocardial ultrastructures wore relatively well preserved in isthemic preconditioned hearts. N6_nitro-L-arginine methyl ester(L-NAME) an inhibitor of L-arginine citric oxide pathway, was infused at a rate O.Smllmin In a dose of 10mg kg-1 before the initial ischemic preconditioning. neither the protection of cardiac function nor the reduction of LDH releAse in ischemic preconditioning hearts was altered in the presence of added L-NAME On ultrastructural finding, the preservation of morphology in ischemic preconditioning heart was not change by the pretreatment of L-UAME. The failure of the WO synthesis inhibitor to reduce t e effect of ischemic preconditioning may be related to be species specific in that NO may allot be the trigger for ischemic preconditioning in rats.

• Journal of Korean Neurosurgical Society
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• v.30 no.8
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• pp.976-980
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• 2001

Objectives : For Parkinsonian patients who had not reacted favorably on drug therapy are good candidate for ventroposterolateral pallidotomy, although not curative. We studied these patients after unilateral pallidotomy, to confirm the effectiveness and safety of this procedure. Methods : We evaluated the 17 patients with idiopathic Parkinson's diesease who had undergone unilateral posteroventral pallidotomy. All patients responded to levodopa initially. Mean age was 55 years(38-75years), and mean duration of disease was 9.8 years(3-20years). Pre-and postoperative evaluation at 3 month intervals included Unified Parkinson's Disease Rating scale(UPDRS) scoring, Hoehn and Yahr(H & Y) staging, and neuropsychological examinations. Results : Pallidotomy significantly improved parkinsonian symptom(tremor, rigidity, bradykinesia, dyskinesia, sensory symptom). Nine of 10 patients who showed dyskinesia preoperatively significant improvement. The mean dose of levodopa in 9 patients was lowered. The mean H & Y score and UPDRS score were improved in on and/or off time in 15 patients. Among patients who were not improved, one patient worsened, and the others showed no change. The mean overall UPDRS off score changed from 76 preoperatively to 44(33%) at 6 months and from 70 to 52(25%) at 1 year. Transient surgical morbidity was showen in four patients and included dysarthria, hypotonia and confusion. Conclusion : We conclude that pallidotomy is safe and effective in patients who have levodopa-reponsive parkinsonism with severe symptom fluctuation. Unilateral pallidotomy also considered helpful to ipsilateral symptom. Unilateral pallidotomy can improve all of parkinsonian's symptom and allow to reduce the levodopa medication. Most of patients show satisfactory results.

• Journal of Korean Neurosurgical Society
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• v.30 no.1
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• pp.41-46
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• 2001

Objective : The exact position of the lesion during the pallidotomy is critical to obtain the clinical improvement of parkinson's disease without damage to surrounding structure. Ventriculogrphy, CT(computed tomograpy) or MRI(magnetic resonance imaging) have been used to determine the initial coordinates of stereotactic target for pallidotomy. The goal of this study was to determine whether microelectrode recording significantly improves the neurophysiologic localization of the target obtained from MRI. Methods : Twenty patients were studied. They underwent a unilateral pallidotomy. Leksell frame was applied and T1 axial images parallel to the AC-PC(anterior commissure-posterior commissure) plane using a 1.5 Tesla MRI with 3mm slice thickness were obtained. Anteroposterior coordinate of target was chosen at 2mm in front of the midcommissural point and lateral coordinate between 19 and 22mm from the midline. The vertical coordinate was calculated on coronal slice using a fast spin echo inversion recovery sequence(FSEIR) related to the position of the choroidal fissure and ranged over 4-5mm below the AC-PC plane. Confirmation of the anatomical target was done on axial slices using the same FSEIR sequence . Microrecording was done at the pallidum contralateral to the symptomatic side using an electrode with a tip diameter of $1{{\mu}m}$ diameter tip and 1.1-1.4 mOhm impedance at 1000Hz. Electrophysiologic localization of the target was also confirmed intraoperatively by macrostimulation. Results : Microrecording techniques were reliable to define the transition from the base of the pallidum which was characterized by the disappearance of spike activity and by the change of the audible background activity. Signals from high amplitude neurons firing at 200-400Hz were recorded in the pallidal base. X, Y and Z coordinates of target obtained from the MRI were within 1mm from the X, Y, Z coordinates obtained with microrecording in 16 patients (80%), 15 patients(75%), 10 patients(50%) respectively. The difference of Y coordinate between on MRI and on microrecording was 4mm in only one patient. Conclusion : The MRI was accurate to localize the target within 1mm of the error from microrecording target in 70% of the patients. 4mm discrepancy was observed only once. We conclude that MRI alone can be used to determine the target for pallidotomy in most patients. However, microrecording technique can still be extremely valuable in patents with aberrant anatomy or unusual MRI coordinates. We also consider physiologic confirmation of the target using macrostimulation to be mandatory in all cases.

• Parasites, Hosts and Diseases
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• v.23 no.1
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• pp.58-72
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• 1985

A histopathological study was carried out on the duodenum of mice and rats experimentally infected by F. seoulensis. Each mouse was infected with 500 metacercariae and killed after 1, 2, 3 days, 1 and 2 weeks from infection. Each rat was given 1, 000 metacercariae and was examined after 1, 2 and 4 weeks from infection. The duodenal tissue sections of mice and rats were stained with hematoxylin eosin, and PAS stained for the rats of 1 week group. The pathological findings are summarized as below. 1. There were no differences in mucosal findings between the mice and the rats, and between the location of duodenum, 1 and 5 em distal to the pylorus. 2. Each worm embraced a villus exclusively with its foliate fore body which was inserted into the intervillous spaces. The fluke pinched villous epithelia using its oral and ventral suckers. The tribocytic organ destroyed the villous epithelia deeply up to the stroma after 3 days from infection. 3. Apparent villous changes were observed in the mice after 3 days from infection. Villous changes were shortening, widening, blunting or fusion. The villous stroma showed edema, microscopic hemorrhage, capillary congestion, dilatation of lymphatics and inflammatory cell infiltration. The cells were lymphocytes, plasma cells, eosinophils and giant cells. Rarely submucosal and trans:nural inflammation was encountered.

• The Korean Journal of Physiology
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• v.22 no.2
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• pp.273-280
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• 1988

This study was undertaken to investigate the effect of the medial amygdaloid nucleus on the pancreatic exocrine secretion and plasma secretin concentration in 44 male albino rats. Twenty-three rats in which the medial amygdaloid nucleus was damaged bilaterally by radio frequency a.c. through stereotaxically inserted electrodes (medical amygdaloid group, MA) and twenty-one rats which received the same operation without damage (operated control, OC), were prepared. Under urethan anesthesia, 0.01 N hydrochloric acid (HCl) or physiological saline (0.9% NaCl) was infused at a rate of 0.18 ml/min into the duodenum for 20 minutes. Pancreatic jucie was collected for the 20 min infusion period. After collection of pancreatic juice, blood was sampled from the abdominal aorta for the radioimmunoassay of plasma secretin concentration. In the MA group, the exocrine pancreatic secretory response to 0.01 N HCI as well as saline infusion was significantly inhibited compared with that in the OC group. The pancreatic protein output of the MA group significantly decreased after the saline infusion and tended to decrease after the 0.01 N HCI infusion, compared with that of the OC group. However, there was no significant difference in plasma secretin concentration between the two groups. Therefore it is strongly suggested that the rat medial amygdaloid nucleus has a facilitatory influence on both basal and acid-stimulated pancreatic exocrine secretion, but the releasing mechanism of secretin appears not to be involved in the influence.