• Investigative Magnetic Resonance Imaging
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• v.15 no.2
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• pp.123-129
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• 2011

Purpose : To compare lumbar disc changes between initial lumbar spine (L-spine) MRI and follow-up (f/u) MRI that were performed due to recurred backaches. Materials and Methods : A total 50 patients who had undergone f/u L-spine MRI were retrospectively reviewed. Five discs (L1-S1) were surveyed in each f/u MRI. Lumbar disc changes were defined as no change, aggravations, or improvements compared to initial disc states. These states were defined on the basis of morphologic status and disc levels. Results : In a total of 250 discs in 50 patients, 31 discs (12.4%) showed morphologic changes of disc lesions, whereas 219 discs (87.6 %) showed no changes. Among the 31 disc lesions, 24 were aggravated and 7 were partially improved. And on the basis of disc status, initially abnormal discs revealed any morphologic changes of the degree of disc herniation. A total of 33.3% of the morphologic changes are noted in initially extruded discs. Fifteen morphologic changes of disc lesions were located at the L4-5 level. Conclusion : Our results suggest that correlations between lumbar disc herniations and back pain symptoms are limited, and that evaluations of extra disc lesions are required.

• The Korean Journal of Pain
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• v.18 no.2
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• pp.133-137
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• 2005

Background: Cannabinoids have shown antinociceptive action. The aims of this study were to examine the effect of chronic infusion of a cannabinoids receptors agonist (WIN 55,212-2) for thermal nociception at the spinal level, and to also observe the development of toxicity. Methods: Male Sprague-Dawley rats were implanted with lumbar intrathecal catheters with the nociceptive response (withdrawal response latency) determined by exposing the plantar surface of the hindpaw to radiant heat. Initially, the effect of intrathecal WIN 55,212-2 was evaluated followed by the change in the effect at 1, 2, 3 and 4 weeks after repeated infusion. Finally, the histopathological findings were assessed 1 and 4 weeks following the infusion of WIN 55,212-2. Results: Intrathecal WIN 55,212-2 was found to produce a limited antinociception during the thermal test. %MPE of WIN 55,212-2 at 1, 2, 3, and 4 weeks after infusion was not different from each other. No abnormal pathological findings were observed following a chronic intrathecal infusion of WIN 55,212-2. Conclusions: WIN 55,212-2, a cannabinoids receptors agonist, may be useful in the management of thermal nociception, without changing the effectiveness or causing the toxicity following a chronic infusion at the spinal level.

• Journal of the Korean Society of Safety
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• v.32 no.4
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• pp.46-52
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• 2017

Sediment exchange in river has been affected by artificial changes such as dredging and abnormal climate changes like intense rainfall. Over last decades in Korea, there were many constructions, restoration or rehabilitation in rivers. Therefore, deposition and erosion become more actively occurred than before, which may threaten the river safety such as flood defense. For safety's sake, the dredging of river bed, which is considered as the most typical measure, has been increased to extend hydraulic conveyance compared with previous conditions. However, since it might change the sediment mechanism, there would be another risk at which unexpected side effects such as headward erosion could be occurred. Particularly, sedimentation at abrupt expansion region is able to lead to hydraulic characteristics like water elevation in the upstream region in the beginning of dredging, which, however, has been barely studied in this field. Therefore in this study, the relationship between sediment mechanism at dredging section and hydraulic characteristics in upstream region were presented through numerical simulations in the idealized abruptly widen channel using Delft3D. The ideal channel of 2,000 m length with each side angle of 45 degrees at abruptly widen expansion region was employed to consider the sediment angle of repose. The sensitivity analysis was performed on the dimensionless factors consisted of upstream and downstream depths($h_u$, $h_d$), width($w_u$, $w_d$), water level(H), flow rate(Q) and discharge of sediment($Q_s$). And the sedimentation amount at dredging and the upstream hydraulic characteristics were investigated through that analysis. It showed that $h_d/h_u$, $H/h_u$ and $w_d/w_u$ were more influential in sequence of effect on sedimentation amount, while $h_d/h_u$, $w_d/w_u$ and $H/h_u$ on upstream region. It means that $h_d/h_u$ was revealed as the most significant factors on sedimentation, also it would most highly affect the rising of water level upstream.

• The Journal of the Korean life insurance medical association
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• v.2 no.1
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• pp.218-232
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• 1985

Congenital hereditary disease is in devided into Infantile type and Adult type, Adult type is hidden for many years and keeps normal renal function till middle age. Cyst is stimultaneously made in both sides and becomes lowered in renal function in 30's to 40's. Infantile type is generally born with the big kidneys, renal failure, undergrowth of intrahepatic bile duct. Both infantile and childhood type have ureteral dilatation and portal hypertension In infantile type, it is mostly developed into renal failure, but generally faces death as a result of hepatic disease. The reason of death is that an abnormal condition of recessive autosome affects the liver and kidneys. While the incidence of infantile type is rare as $0.017{\sim}0.07%$ and it is autosomal recessive heredity, Adult type can rarely exist in infantile period. Though it exists in middle period, 50% of patients can live for 2-4 years after the first symptom incidence and 25% can less than 2 years. It is hard to cure completely in medicine and surgery. Three difficulties in familial incidence are comparative decrease of the donor who have no affection on renal transplantation. For another consideration it is to show the family history for several generations. We, the Med. Dept. of Dae Han Kyouk Life Insurance Co. Ltd., used the ultrasonic apparatus in diagnosing the one case of adult type bilateral polycystic kidney and then doubted the family history. As a result of inspecting the family we experienced bilateral polycystic kidney from 3 persons out of 4 who can be inspected. The results are as follows: 1) We could confirm the polycystic kidney from 3 persons out of 4(75%). 2) Then when they came for check up, chief complaint was the pain in all 3 cases(100%). 3) Accompanying disease was hypertension in 2 cases(67%). 4) In early disease incidence, we couldn't observe the specific change in pathological opinion. 5) All 3 cases are not accompanied with cystic lesion in liver, spleen, pancreas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.689-696
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• 2018

System grounding is applied to the neutral point of a power source to secure the from any abnormal voltage and/or grounding fault. System grounding, which is applied mainly in ships is an ungrounded and resistance grounded system. Vessels using the MV power system with 3.3kV, 6.6kV, and 11kV mainly adopt a high resistance grounding system among the resistance grounding systems. The ground fault accounts for 95% of all faults occurring in the electrical system and when a fault occurs, the line-to-ground voltage of the power system is increased excessively, which adversely affects the onboard insulation system. This study analyzed the variation characteristics of the line-to-ground voltage neutral point according to the degree of ground fault in a resistance ground system applied in vessels. For this purpose, the characteristics of the grounding system were first explained, and the modeling of the neutral point potential of the line-to-ground voltage of the resistance grounding system in the vessels was derived. Finally, this study examined how the line-to-ground voltage, line voltage, and neutral point change according to various variable environments through MATLAB simulations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.98-106
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• 2020

This study examined the integrity of diesel engines for underwater vessels through failure analysis, analyzed the causes of abnormal diesel engine stoppage during building and examined the integrity of secondary damages. The diesel engine stoppage was analyzed by checking the temperature change of the piston before and after the abnormality and checking the damage. In addition, in order to analyze the secondary damage caused by the explosion, the tensile and compressive stresses transmitted to the crankshaft, the core part of the diesel engine, were calculated, and the stress distribution was examined through finite element analysis, but the crankshaft was designed by safety. It was confirmed that there was no damage to the crankcase even when the diesel engine was taken out of the ship and closely inspected. The integrity of the crank shaft was verified in advance for the occurrence of diesel engine emergency shutdown accidents through this research result. Therefore, the inspection and restoration were carried out to the minimum extent, and the quality of diesel engines was secured. This study is expected to be used as a reference for ensuring soundness in any future review of diesel engine quality problems.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.5
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• pp.617-628
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• 1998

In order to understand the pathogenetic mechanism of adult respiratory distress syndrome (ARDS), the role of phospholipase A2 (PLA2) in association with oxidative stress was investigated in rats. $Interleukin-1{\alpha}\;(IL-1,\;50\;{\mu}g/rat)$ was used to induce acute lung injury by neutrophilic respiratory burst. Five hours after IL-1 insufflation into trachea, microvascular integrity was disrupted, and protein leakage into the alveolar lumen was followed. An infiltration of neutrophils was clearly observed after IL-1 treatment. It was the origin of the generation of oxygen radicals causing oxidative stress in the lung. IL-1 increased tumor necrosis factor (TNF) and cytokine-induced neutrophil chemoattractant (CINC) in the bronchoalveolar lavage fluid, but mepacrine, a PLA2 inhibitor, did not change the levels of these cytokines. Although IL-1 increased PLA2 activity time-dependently, mepacrine inhibited the activity almost completely. Activation of PLA2 elevated leukotriene C4 and B4 (LTC4 and LTB4), and 6-keto-prostaglandin $F2{\alpha}\;(6-keto-PGF2{\alpha})$ was consumed completely by respiratory burst induced by IL-1. Mepacrine did not alter these changes in the contents of lipid mediators. To estimate the functional changes of alveolar barrier during the oxidative stress, quantitative changes of pulmonary surfactant, activity of gamma glutamyltransferase (GGT), and ultrastructural changes were examined. IL-1 increased the level of phospholipid in the bronchoalveolar lavage (BAL) fluid, which seemed to be caused by abnormal, pathological release of lamellar bodies into the alveolar lumen. Mepacrine recovered the amount of surfactant up to control level. IL-1 decreased GGT activity, while mepacrine restored it. In ultrastructural study, when treated with IL-1, marked necroses of endothelial cells and type II pneumocytes were observed, while mepacrine inhibited these pathological changes. In histochemical electron microscopy, increased generation of oxidants was identified around neutrophils and in the cytoplasm of type II pneumocytes. Mepacrine reduced the generation of oxidants in the tissue produced by neutrophilic respiratory burst. In immunoelectron microscopic study, PLA2 was identified in the cytoplasm of the type II pneumocytes after IL-1 treatment, but mepacrine diminished PLA2 particles in the cytoplasm of the type II pneumocyte. Based on these experimental results, it is suggested that PLA2 plays a pivotal role in inducing acute lung injury mediated by IL-1 through the oxidative stress by neutrophils. By causing endothelial damage, functional changes of pulmonary surfactant and alveolar type I pneumocyte, oxidative stress disrupts microvascular integrity and alveolar barrier.

• Journal of Chest Surgery
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• v.30 no.7
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• pp.713-718
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• 1997

Fracture of the sternum has been considered as a serious injury and also associated with major complications such as myocardial, major thoracic vascular, and spinal injury. Retrospective datas from blunt trauma victims admitted to our hospital were analyzed to determine significance of sternal fractures and possible associated injures. 101 sternal fractures by blunt trauma were admitted from january, 1986 to december, 1995. Frequency was about 3.51 olo of the nonpenetrating chest trauma. The ratio of male to female was 1.82 versus 1. Most common cause in the stemal fracture was high decelerating injury(73 cases). Most common fracture site was sternal body(75 cases). Average days of adm ssion were 26 days. Abnormal ECG findings were sinus bradycardia(Teases), complete or incomplete RBBB(6 cases), sinus tachycardia(4 cases), specific S-T change(3 cases), 1st degree A-V block(2 cases), LVH(1 case), PVC(1 case), and Low voltage(1 case). CPK-MB was increased about 32.Lolo of sternal fractures. Except of expired 2 patients, patients were treated with conservative treatment(94 cases) and open reductions & steel wire fixations(5 cases). Complication after operation was wound infection(1 case). Causes of death were 1 hypovolemia and 1 acute respiratory distress syndrome. In conclusion, although sternal fracture is less frequent, and mostly treats with conservative treatment, it shoed be carefully observed because of critical associated injuries.

• Journal of Korea Water Resources Association
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• v.51 no.8
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• pp.703-711
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• 2018

Water distribution system (WDS) pipe bursts are caused from excessive pressure, pipe aging, and ground shift from temperature change and earthquake. Prompt detection of and response to the failure event help prevent large-scale service interruption and catastrophic sinkhole generation. To that end, this study proposes a improved Western Electric Company (WECO) method to improve the detection effectiveness and efficiency of the original WECO method. The original WECO method is an univariate Statistical Process Control (SPC) technique used for identifying any non-random patterns in system output data. The improved WECO method multiples a threshold modifier (w) to each threshold of WECO sub-rules in order to control the sensitivity of anomaly detection in a water distribution network of interest. The Austin network was used to demonstrated the proposed method in which normal random and abnormal pipe flow data were generated. The best w value was identified from a sensitivity analysis, and the impact of measurement frequency (dt = 5, 10, 15 min etc.) was also investigated. The proposed method was compared to the original WECO method with respect to detection probability, false alarm rate, and averaged detection time. Finally, this study provides a set of guidelines on the use of the WECO method for real-life WDS pipe burst detection.

• Korean Journal of Medicinal Crop Science
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• v.3 no.2
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• pp.146-150
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• 1995

Weed control in the Korean ginseng(Panax ginseng C.A. Meyer) garden is more difficult than in other crops because the ginseng is a perennial crop and has to be cultivated under the artificial shading. As hand weeding is the only practical means to control weed after crop establishment, a selective herbicide would greatly simplify the control of weed in ginseng garden. In an exploratory experiment, the hervicide Fluazifop-butyl was found to be selectively safe for the Korean ginseng plants. Various rates of Fluazifop-butyl were sprayed on 2-, 3-, and 4-years old ginseng plants as a foliar spray to detect crop injury and to difine their critical concentration. No apparent injury to the ginseng plant was noticable even the doubled application rate of Fluazifop-butyl the based on recommended dosage. Neither abnormal foliar change nor any inhibition in leaf and stem growth was resulted for 2-, 3-, and 4-years old ginseng plants treated with Fluazifop-butyl tripled the recommended usage. The foliar treatments of Fluazifop-butyl did not influence the photosynthesis ability but inhibited the respiration of the ginseng leaf.