• Journal of the korean veterinary medical association
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• v.46 no.6
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• pp.527-543
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• 2010

구제역은 소 돼지 사슴 면양 산양 고라니 노루 등 우제류 동물에서 발생하는 제1종 가축전염병으로 빠른 시간내에 동물의 입 발굽 젖꼭지 등에 수포를 형성하는 것이 특징이다. 감염된 소의 혓바닥, 잇몸, 입술, 입 내부점막, 주둥이에 크기가 다양한 수포가 형성된다. 심한 경우에 혀 전체 넓은 부위에서 궤양이 형성될 수 있다. 수포는 24시간이내에 정상적으로는 파열되며, 그 수포액은 $10^8/ml$의 역가를 갖는 바이러스를 함유한다. 상피가 떨어지고, 유연이 심해지며, 타액이 입 주변에 흔건히 흘러내린다. 입 주변 병변과 동시 또는 이어서 수포가 발굽에 형성되며, 부분적으로 발굽갓띠 또는 제부의 갈라진 틈에서 생성되어 통증과 파행의 원인이 된다. 수포는 보통 유두와 유방에 발생되며, 때로는 세균성 유방염을 발생시킨다. 생산성의 감소는 보통 25% 정도로 추정된다. 돼지는 초기에 파행, 발열, 의기소침, 식욕부진이 있다. 소 보다 발굽에서 더욱 증상이 심하다. 유두, 유선, 콧등에 수포가 형성된다. 혀의 병변은 소보다 심하지 않다. 잠복기가 2~14일 (소에서의 약 6.2일, 돼지에서는 약 10.2일)로 짧고, 전파가 매우 빠르며 경제적 피해가 크기 때문에 국제 교역에서도 규제대상이 되는 질병이다. 구제역의 병인체는 피코르나바이러스과 아프토바이러스속에 속하는 구제역 바이러스로 현재까지 7개의 혈청형(A, O, C, Asia 1, SAT 1, SAT 2 및 SAT 3)이 알려져 있다. 이 전염병은 동물전염병 중에서 가장 악명 높은 전염병이다. 세계동물보건기구 (OIE)에서도 각 국간에 국제적인 위협을 최소화하기 위하여 질병의 발생을 보고해야 하는 질병으로 특별 관리하고 있다. 2006년 이후 최근까지 아시아 지역에서 지속적으로 많은 발생을 보이고 있다. 금년 들어 중국, 대만, 일본, 몽골, 우리나라까지 발생되어 이 질병의 위험성에 대하여 다시 한번 생각하게 하였다. 구제역의 재발방지를 위하여 최근 동북아시아 지역의 발생상황과 향후 구제역의 발생억제 또는 발생시 긴급 대응을 위하여 해야 할 일은 무엇인지 알아보자.

• Journal of the Korean Institute of Gas
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• v.15 no.2
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• pp.69-74
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• 2011

As a way to propose a method for the establishment of practical damage-minimizing plan for chemical plants, the release scenario was established by using API-581 BRD and the effect zone was estimated by the KS-RBI program supporting the quantitative cause analysis. And the risk assessment was performed. As a result, we found that to minimize the damage of a chemical plant, it is effective to use four release hole diameters (small, medium, large and rupture) and release time estimated according to the classes of detection and isolation systems. In addition, it can be safely said that through appling the damage areas considering weighted average by failure frequency and worst-case simultaneously, industrial sites can come up with the effective emergency response plan.

• Journal of Korea Water Resources Association
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• v.39 no.1 s.162
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• pp.35-46
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• 2006

In this study, we proposed a layout of the integrated decision support system in order to prevent the contamination and to manage risk in water supply networks for safe and smooth water supply. We evaluated the priority of risk factors to detect anomaly in water supply networks using PROMETHEE and ANP techniques, which are applied to various Multi-Criteria Decision Making area in Europe and America. To develop the model, we selected pH, residual chlorine concentration, discharge, hydraulic pressure, electrical conductivity, turbidity, block leakage and water temperature as the key data item. We also chose pipe corrosion, pipe burst and water pollution in pipe as the criteria and then we present the results of PROMETHEE and ANP analysis. The evaluation results of the priority of risk factors in water supply networks will provide basic data to establish a contingency plan for accidents so that we can establish the specific emergency response procedures.

• Journal of the Korean Institute of Gas
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• v.25 no.4
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• pp.1-9
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• 2021

The process and facilities of modern chemical plants are becoming increasingly complex, there is possibility of potential risk. Internal chemicals generate stress concentration when operated due to turbulence, laminar flow, pressure, temperature, friction, etc. It causes cumulative fatigue damage, which can damage or rupture chemical facilities and devices. The statistics of chemical accidents found that the highest rate of occurrence was in summer, and in the last five years statistics on chemical accidents, leakage incidents make up a decent percentage of accidents. Chemical leaks can cause serious human damage and economic damage, including explosions and environmental pollution. In this study, based on the leak accident of chemical plant, the risk analysis, and damage effects assessment were estimated using a 3D scanner and FLACS. As a result, if chemicals leak in summer, the risk is higher than in other seasons, the seasonal safety management measures, and countermeasure were estimated.

• Economic and Environmental Geology
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• v.55 no.2
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• pp.183-195
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• 2022

Hydrothermal gold deposits are evidence of intensive fluid flow through fault zones, and the resultant vein structures and textures reflect the fluid redistribution mechanism. This review introduces the suction pump and fault valve models as fluid circulation mechanisms causing hydrothermal gold deposits in the frameworks of the concepts of fault mechanics. The suction pump and fault valve models describe faulting-driven heterogeneous fluid flow and related vein formation mechanisms, accompanied by the cycles of (1) stress accumulation and fluid pressure build-up and (2) seismic rupture and stress/fluid pressure release. The models are available under different geological environments (stress conditions), and the vein structures and textures representing the mechanisms have similarities and differences. The suction pump and fault valve models must help better to interpret the origins of hydrothermal gold deposits in Korea and improve the efficiency of further exploration.

• Journal of the Korean Orthopaedic Association
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• v.54 no.6
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• pp.475-477
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• 2019

Stem cell research arose from the need to explore new therapeutic possibilities for intractable and lethal diseases. Although musculoskeletal disorders are basically nonlethal, their high prevalence and the relative ease of performing clinical trials have facilitated the clinical application of stem cells in this field. On the other hand, despite the plethora of in vitro and preclinical studies in stem cell research for regenerative medicine in the musculoskeletal system, few reliable clinical studies have been published. Stem cell therapy can be applied locally for bone, cartilage, and tendon regeneration. The candidate disease modalities in bone regeneration include large bone defects, nonunion of fractures, and osteonecrosis. Focal osteochondral defect and osteoarthritis are the current targets for cartilage regeneration. For tendon regeneration, bone-tendon junction problems, such as rotator cuff tears are hot topics in clinical research. To date, the literature supporting stem cell-based therapies comprises mostly case reports or case series.

• Journal of the Korean Institute of Gas
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• v.28 no.2
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• pp.47-55
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• 2024

More than 100 liquefied hydrogen tanks are expected to be introduced in Korea by 2030. Since liquefied hydrogen is stored in a vacuum insulation structure tank at -253℃, there is a possibility of a major disaster in which the tank bursts if there is a problem with insulation. Therefore, the law stipulates that PRV should be installed as the last bastion. It is important to note that in the case of liquefied hydrogen, it becomes useless if the pressure drop of the pipe is ignored and the capacity is calculated incorrectly. In CGA S-1.3, the pressure drop rate of the PRV inlet and outlet pipes is set to less than 3% and less than 10%, respectively. However, there is an interdependence between the amount of pressure drop and the flow rate of the pipe, making it impossible to calculate these values at once. Therefore, we developed a simulator that calculates the pressure loss rate of PRV system using MATLAB/Simulink and evaluated the sensitivity of the pressure drop rate to design elements.

• The Journal of the Korean bone and joint tumor society
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• v.9 no.1
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• pp.52-60
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• 2003

Purpose: To analyse their end results and also to differentiate the single or multiple giant cell tumor(GCT) of tendon sheath in hand. Materials & Methods: Total 21 cases with GCT of tendon sheath in hand were treated surgically and analyzed their end results with clinically, radiologically and pathologically to allowed for average 16 months after surgical excision. Results: The finger flexor tendons, especially on index and ring finger, involving distal interphalangeal joint and mid-phalanges in fourth decades (average age of 47 years old) were frequently involved, and the mass was not exceed than 2 cm in size, fixed on tendon sheath with rubbery hard tenderness but rare bony involvements except 4 cases of bony erosion and cortical perforation. The three cases with multiple GCT of hand was also combined with familial hypercholesterolemia, and are commonly involved the extensor tendons as well as achilles tendons bilaterally, treated with partial excision because of multiplicity. Average 16 months after surgical excision for single GCT cases was followed and showed the recurrence in 3 cases(3/18,16.7%), treated with wide excision. The single and multifocal GCT are similar in pathologic changes but different soft tissue tumors in their pathogenesis, treatment and prognosis. Conclusion: Incomplete excision of GCT of tendon sheath in hand are thought to be the cause of recurrence, especially in cases with incomplete lesional excision, in multilobular and bony involvement etc. So careful wide excision is necessary to prevent the recurrence.

• Investigative Magnetic Resonance Imaging
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• v.10 no.2
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• pp.98-107
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• 2006

Magnetization Transfer (MT) imaging generates contrast dependent on the phenomenon of magnetization exchange between free water proton and restricted proton in macromolecules. In biological materials in knee, MT or cross-relaxation is commonly modeled using two spin pools identified by their different T2 relaxation times. Two models for cross-relaxation emphasize the role of proton chemical exchange between protons of water and exchangeable protons on macromolecules, as well as through dipole-dipole interaction between the water and macromolecule protons. The most essential tool in medical image manipulation is the ability to adjust the contrast and intensity. Thus, it is desirable to adjust the contrast and intensity of an image interactively in the real time. The proton density (PD) and T2-weighted SE MR images allow the depiction of knee structures and can demonstrate defects and gross morphologic changes. The PD- and T2-weighted images also show the cartilage internal pathology due to the more intermediate signal of the knee joint in these sequences. Suppression of fat extends the dynamic range of tissue contrast, removes chemical shift artifacts, and decreases motion-related ghost artifacts. Like fat saturation, phase sensitive methods are also based on the difference in precession frequencies of water and fat. In this study, phase sensitive methods look at the phase difference that is accumulated in time as a result of Larmor frequency differences rather than using this difference directly. Although how MT work was given with clinical evidence that leads to quantitative model for MT in tissues, the mathematical formalism used to describe the MT effect applies to explaining to evaluate knee disorder, such as anterior cruciate ligament (ACL) tear and meniscal tear. Calculation of the effect of the effect of the MT saturation is given in the magnetization transfer ratio (MTR) which is a quantitative measure of the relative decrease in signal intensity due to the MT pulse.

• Korean Journal of Animal Reproduction
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• v.23 no.1
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• pp.75-84
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• 1999

This study assessed development in vitro of pronuclear(PN) stage embryos cryopreserved by the method of either vitrification or slow freezing, by using of different cryoprotectants, and equilibration and cooling rate, in rabbit. Ethyleneglycol- ficoll- sucrose(EFS) or ethyleneglycol- polyvinylpyrrolidone - galactose- (EPG-I) for vitrification, and EPG- II for slow freezing as cryoprotectant were used. The pronuclear embryos were exposed to EFS for 0 to 5 min and diluted with D-PBS and/or pre-dilution with 0.5 M sucrose. To examine the viability of frozen-thawed embryos, PN embryos were co-cultured with bovine oviductal epitherial cell(BOEC) for 5 days to hatching blastocyst stage in 39 $^{\circ}C$ 5% $CO_2$incubator. The results obtained were as follows: The dilution with 0.5 M sucrose and D-PBS after the exposure to EFS for 1.0 min resulted in no significant(P＜0.05) decrease in the development of PN embryos to hatching blastocyst(72.0%), compared with controls. The development of PN embryos cryopreserved to hatching blastocyst was not significantly (P＜0.05) different between EFS for 1.0 min(72.0%), EPG-I for 1.0 min(72.0%) and EPG-II for 30 min(66. 7%). The post-thaw development of PN embryos to hatching blastocyst was similarly very low as 6.1% and 11.5% in vitrification with EFS and slow freezing with EPG-II, respectively. The incidence of post-thaw zona-crack in PN embryos cryopreserved by slow freezing with plunging to liquid nitrogen at －35$^{\circ}C$ was signicantly(P＜0.05) higher(25.0%), compared with －85$^{\circ}C$ (1.9%). These results indicated that the rabbit PN embryos could be cryopreserved with either vitrification or slow freezing procedure, and frozen PN embryos could be successfully developed in vitro to haching blastocyst. but the post-thaw development of cryopreserved PN embryos was still very low under the present conditions.