• The Korea Journal of Herbology
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• v.28 no.6
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• pp.145-153
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• 2013

Objectives : Neuroinflammation is characterized by microglial activation and the expression of major inflammatory mediators. The present study investigated the inhibitory effect of ginsenoside Rg1 ($GRg_1$), a principle active ingredient in Panax ginseng, on pro-inflammatory cytokines and microglial activation induced by systemic lipopolysaccharide (LPS) treatment in the mouse brain tissue. Methods : Varying doses of $GRg_1$ was orally administered (10, 20, and 30 mg/kg) 1 h before the LPS injection (3 mg/kg, intraperitoneally). The mRNA expression of pro-inflammatory cytokines in the brain tissue was measured using the quantitative real-time PCR method at 4 h after the LPS injection, Microglial activation was evaluated using western blotting and immunohistochemistry against ionized calcium binding adaptor molecule 1 (Iba1) in the brain tissue. Cyclooxigenase-2 (COX-2) expressions also observed using western blotting and immunohistochemistry at 4 h after the LPS injection, In addition, double-immunofluorescent labeling of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and COX-2 with microglia and neurons was processed in the brain tissue. Results : $GRg_1$ (30 mg/kg) significantly attenuated the upregulation of TNF-${\alpha}$, interleukin (IL)-$1{\beta}$ and IL-6 mRNA in the brain tissue at 4 h after LPS injection. Morphological activation and Iba1 protein expression of microglia induced by systemic LPS injection were reduced by the $GRg_1$ (30 mg/kg) treatment. Upregulation of COX-2 protein expression in the brain tissue was also attenuated by the $GRg_1$ (30 mg/kg) treatment. Conclusion : The results suggest that $GRg_1$ is effective in the early stage of neuroinflammation which causes neurodegenerative diseases.

• Journal of Korean Neurosurgical Society
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• v.51 no.5
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• pp.312-315
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• 2012

We report magnetic resonance image (MRI) and magnetic resonance spectroscopy (MRS) findings in a patient of cerebral fat embolism (CFE) occurred in a 26-year-old woman after an autologous fat injection into the face. After initial neurologic symptom onset, MRI and MRS data were obtained two times to investigate repeated CFE. We obtained the MRS data in the two different time intervals and two different echo times to compare the lesions with normal brain parenchyma. The results of MRS data showed that a decrease in N-acetyl-aspartate, an increase in lactate and a very high early peak of free lipids between 0.9 and 1.4 ppm were obtained at the acute infarcted lesion as compared with normal brain parenchyma. In addition, these findings were more clearly detected on short echo time spectrum rather than long spectrum. A close relationship between the clinical manifestations and MRI and MRS findings of the brain can helpful to distinguish CFE with other conditions and to evaluate the cause materials of infarctions rather than conventional MRI or diffusion-weighted imaging.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.3
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• pp.249-253
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• 2009

Langerhans cell histiocytosis(LCH), previously known as histiocytosis X, is rare, proliferative disorder in which the accumulation of pathologic Langerhans cell leads to tissue infiltration and destruction. The jaw is involved 10~20% of all LCH and most common oral symptoms are jaw swelling or a palpation mass. Most of subjects are males and disease appears to start before the age of 10 years. An 11 years old girl was referred from pediatric department. Histological examination confirmed the diagnosis LCH. She was treated intra-lesional injection of corticosteroid. The overall outcome was excellent. After a follow-up period of 20 month, the patient present with no evidence of residual disease on Panoramic view and whole body bone scan. We report this early recognized LCH case treated by corticoid injection in good progress with literature review.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.1
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• pp.15-19
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• 2002

The role of vascular NAD(P)H oxidase in subarachnoid hemorrhage (SAH)-induced vasospasm in the basilar artery was examined in a rat model. Arterial vasospasm characterized by increased wall thickness and decreased lumen size was observed at 5 to 7 days after $2^{nd}$ injection of blood into cisterna magna, and these changes were significantly ameliorated by pretreatment of diphenyleneiodonium $(DPI,\;25\;{\mu}l\;of\;100\;{\mu}M),$ an inhibitor of NAD(P)H oxidase. To determine the time course of changes in the vascular NAD(P)H oxidase activity, cerebral vasculature was isolated at different time intervals from 12 hrs to 14 days after injection of autologous blood. At 24 hrs after the second injection of blood, the NAD(P)H oxidase activity was markedly increased with an enhanced membrane translocation of p47phox, but by 48 hours both the enzyme activity and p47phox translocation regained normal values, and were remained unchanged up to 14 days after SAH. However, no significant changes in the expression of p22phox mRNA was observed throughout the experiments. These findings suggest that the activation of NAD(P)H oxidase by which assembly of the oxidase components enhanced and subsequent production of superoxide in the early stages of SAH might contribute to the delayed cerebral vasospasm in SAH rats.

• Journal of ILASS-Korea
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• v.17 no.2
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• pp.71-76
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• 2012

The aim of this work was to investigate the combustion and nanoparticle emission characteristics of premixed charge compression ignition (PCCI) combustion at various test conditions using a single cylinder common-rail diesel engine. In order to create the homogeneity of fuel-air mixture, the premixed fuel (gasoline) was injected into premixing chamber during the intake process and then the diesel fuel was directly injected into the combustion chamber as an ignition source for the gasoline premixture. From these results, it revealed that the ignition delays and combustion durations were gradually prolonged and the peak combustion pressure were increased because diesel fuel was injected early injection timing with the increase of premixed ratio. In addition, as the increase of premixed ratio, total particle number is generally decreased and particle volume also indicated low levels at the direct injection timing from BTDC $20^{\circ}$ to TDC. At further advanced injection timing, total particle number and volume were generally increased

• Korean Journal of Veterinary Research
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• v.51 no.3
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• pp.239-241
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• 2011

In this study, we investigated the kinetics of tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6 and high mobility group box 1 (HMGB1) concentrations in a 48-h model of canine endotoxemia by lipopolysaccharide (LPS) injection. Four healthy beagles were slowly administered 1 mg/kg of LPS diluted in normal saline, while two others were administered normal saline as controls. Blood collection was performed at 0 h (baseline), 1 h and 3 h (for TNF-${\alpha}$), 6 h, 12 h, 24 h and 48 h of the experiment, and cytokine levels were determined using the sandwich ELISA method. Early increments of TNF-${\alpha}$ and IL-6 were observed (< 3 h), but HMGB1 levels increased the most at 12 h of the experiment and gradually decreased until 48 h. During the whole experiment, IL-6 and HMGB1 were sustained over 12 h of LPS injection, whereas TNF-${\alpha}$ decreased within 6 h of LPS injection. Taken together, canine HMGB1 levels increase relatively late (< 12 h) and sustained longer than TNF-${\alpha}$ and IL-6 in response to endotoxin. This is the first study to evaluate canine HMGB1 cytokine from endotoxemia in dogs.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.1
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• pp.1-8
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• 2011

Advanced SITs of the evolutionary PWRs have the advantage that they can passively control the ECC water discharge flow rate. Thus, the LPSI pumps can be eliminated from the safety injection system owing to the benefit of the advanced SITs. In the present study, a passive sealing plate was designed in order to overcome the shortcoming of the advanced SITs, i.e., the early nitrogen discharge through the stand pipe. The operating principle of the sealing plate depends only on the natural phenomena of buoyancy and gravity. The performance of the sealing plate was evaluated using the VAPER test facility, equipped with a full-scale SIT. It was verified that the passive sealing plate effectively prevented the air discharge during the entire duration of the ECC water discharge. Also, the major performance parameters of the advanced SIT were not changed with the installation of the sealing plate.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.169-175
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• 2013

CRDi technology of diesel engine was developed from in the early 2000s due to a need to increase fuel efficiency and environment care. Especially, high-pressure fuel injection system in CRDi system which has a fuel injection unit including an injector, a fuel pump and common-rail, etc. becomes possible to make the exhaust gas clean as well as power improvement. In this study, comparison of dynamic characteristics of servo-hydraulic piezo-driven injector with 3-way and bypass-circuit type was analyzed by using the AMESim code. As results of this study, it found the bypass-circuit inside servo-hydraulic piezo injector can cause a faster injection response than that of the 3-way type. Also it was shown that bypass-circuit type had better control capability due to hydraulic bypass system.

• Nuclear Engineering and Technology
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• v.33 no.1
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• pp.12-24
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• 2001

The post-LOCA long term cooling (LTC) performance of the Korean Standard Nuclear Power Plant (KSNPP) is analyzed for both small break loss-of-coolant accidents (LOCA) and large break LOCA at cold leg. The RELAP5/MOD3.2.2 beta code is used to calculate the LTC sequences based on the LTC plan of the Korean Standard Nuclear Power Plants (KSNPP). A standard input model is developed such that LOCA and the followed LTC sequence can be calculated in a single run for both small break LOCA and large break LOCA. A spectrum of small break LOCA ranging from \ulcorner.02 to 0.5 k2 of break area and a double-ended guillotine break are analyzed. Through the code calculations, the thermal-hydraulic behavior and the boron behavior are evaluated and the effect of the important action including the safety injection tank (SIT isolation and the simultaneous injection in LTC procedure is investigated. As a result, it is found that the sufficient margin is available in avoiding the boron precipitation in the core. It is also found that a further specific condition for the SIT isolation action need to be setup and it is recommended that the early initiation of the simultaneous injection be taken for larger break LTC sequences.

• Nuclear Engineering and Technology
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• v.45 no.2
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• pp.237-248
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• 2013

Thermal stratification has continuously caused several piping failures in nuclear power plants since the early 1980s. However, this critical thermal effect was not considered when the old nuclear power plants were designed. Therefore, it is urgent to evaluate this unexpected thermal effect on the structural integrity of piping systems. In this paper, the thermal effects of stratified flow in two different safety injection piping systems were investigated by using a coupled CFD-FE method. Since stratified flow is generally generated by turbulent penetration and/or valve leakage, thermal stress analyses as well as CFD analyses were carried out considering these two primary causes. Numerical results show that the most critical factor governing thermal stratification is valve leakage and that temperature distribution significantly changes according to the leakage path. In particular, in-leakage has a high possibility of causing considerable structural problems in RCS piping.