• The Journal of Engineering Geology
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• v.23 no.3
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• pp.217-225
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• 2013

We carried out geometrical, kinematic, and geomechanical analyses on a lineament (the Imgok fault) near Gangneung, observed in ASTER images and aerial photographs, and field surveys. Earthquake focal mechanism solutions, used to estimate the present-day stress state, revealed that the direction of maximum compression is approximately N$70^{\circ}$E and that the stress condition is in favor of either strike-slip or reverse movement on the fault. The strike of the fault is not ideal for slip under the present-day stress field and thus the fault has a low slip tendency. However, the fault may be able to slip if the frictional coefficient (${\mu}$), representing the resistance of the fault to slip, is sufficiently low (e.g., ${\mu}$ < 0.25).

• Journal of Korean Dental Science
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• v.7 no.2
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• pp.94-98
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• 2014

Numerous oral and maxillofacial surgeons have found facial space infections after tooth extraction. Most of these infections can be managed easily, but some of them could be life-threatening. Among the facial infections, temporal space infections are rare. Most temporal space infections could be observed as secondary to maxillary third molar infections, maxillary sinusitis, and maxillary sinus fractures. Note, however, that there are insufficient studies on temporal space abscess due to mandibular second molars, especially with acupuncture. A 74-year-old female came to our hospital with severe trismus and facial swelling on the right temporal, buccal, posterior auricular, and cervical regions. The patient had undergone extraction of tooth #47 secondary to dental caries by a general dentist about a month ago. After the dental procedure, the patient had been treated with acupuncture therapy around the right temporomandibular joint area at the oriental medicine clinic. We performed emergency incision and drainage under general anesthesia and started antibiotic treatment with IV ampicillin/sulbactam 3 g every 24 hours and vancomycin 1 g every 24 hours for 5 days. The patient's symptoms subsided and ultimately disappeared. Temporal space abscess after mandibular molar extraction is quite rare. In this case, the spreading mechanism against gravity is considered to be acupuncture therapy.

• Journal of the Semiconductor & Display Technology
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• v.10 no.1
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• pp.33-41
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• 2011

Due to the recent quantum leaps forward in bio-, nano-, and information-technologies (BT, NT and IT), the precisionization and miniaturization of mechanical and electrical components are in high demand. In particular, the ITrelated equipments that take a great part in our domestic industry are in the area requiring high precision technologies. As a consequence, the researches on the development vibration isolation systems that diminish external disturbance or internal vibration are highly required. Among the components comprising the vibration isolation system, air spring has become on a focal point for the researchers due to its merits. This air spring is able to support heavy loads, keep a low natural frequency despite of having a lower value of stiffness, and control the performance of vibration isolation. However, sometimes the sole use of air spring is in demand due to some economic reasons. Under this circumstance, the damping effect of sole air spring may not enough to reduce sufficient amount of vibration. In this study, the air spring mount system connecting with an external chamber is proposed to increase or control the damping effect. To investigate its damping mechanism, the thermal and dynamic behaviors of the system is examined through a theoretical modeling approach in this part of research. In this approach, thermomechanical and Helmholtz resonator type models are to be employed for the air spring/external chambers and connecting tube system, respectively. The frequency response functions (FRFs) derived from the modeling effort are evaluated with physical parametric values and the effects of connecting tube length on these FRFs are identified through computer simulations.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.208.2-208.2
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• 2012

The Slewing Mirror Telescope (SMT) is a key telescope of Ultra-Fast Flash Observatory (UFFO) space project to explore the first sub-minute or sub-seconds early photons from the Gamma Ray Bursts (GRBs) afterglows. The first realization of UFFO is the 20kg UFFO-Pathfinder (UFFO-P) to be launched on board the Russian Lomonosov satellite in 2013 by the Soyuz-2 rocket. Once the UFFO Burst Alert & Trigger Telescope (UBAT) detects the GRBs, Slewing mirror (SM) will rotate to bring the GRB into the SMT's field of view instead of slewing the entire spacecraft. SMT can image the UV/Optical counterpart with about 4-arcsec accuracy. However it will provide a important understanding of the GRB mechanism by measuring the sub-minute optical photons from GRBs. SMT can respond to the trigger over $35^{\circ}{\times}35^{\circ}$ wide field of view within 1 sec by using Slewing Mirror Stage (SMS). SMT has 10-cm Ritchey-Chretien telescope and $256{\times}256$ pixilated Intensified Charge-Coupled Device (ICCD) on focal plane. In this paper, we discuss the overall design of UFFO-P SMT instrument and payloads development status.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.5
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• pp.225-230
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• 2008

Netrins are secreted molecules and involved in axon guidance, cell migration and tumor development. Recent studies revealed that netrins perform novel functions in such processes as epithelial development and angiogenesis without operating through the classical netrin receptors, DCC (Deleted in Colorectal Cancer) and Unc5h. In the present study, we investigated the roles of netrin-1 and its receptors in cell spreading of human glioblastoma cells, and found that netrin-1 haptotactically enhanced fibronectin-induced cell spreading and focal adhesion formation in U373 glioblastoma cells. Netrin-1 binding to the U373 cell membrane was blocked by an antibody against ${\alpha}v$ integrin subunit, but not by an anti-DCC or anti-Unc5h antibody. In addition, enhancement of the fibronectin response by netrin-1 was abrogated by a function blocking antibody against integrin ${\alpha}v{\beta}3$. Since the ${\alpha}v$ subunit of the integrin family plays an important role in the pathophysiological aspects of cell migration, including tumor angiogenesis and metastasis, our data provide important insight into the molecular mechanism of netrin function.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.5 s.248
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• pp.413-421
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• 2006

The bubble dynamics induced by direct laser heating is experimentally analyzed as a first step to assess the technical feasibility of laser-based ink-jet technology. To understand the interaction between laser light and ink, the absorption spectrum is measured for various ink colors and concentrations. The hydrodynamics of laser-generated bubbles is examined by the laser-flash photography. When an Ar ion laser pulse (wavelength 488 nm) with an output power up to 600 mW is incident on the ink solution through a transparent window, a hemispherical bubble with a diameter up to ${\sim}100{\mu}m$ can be formed with a lifetime in a few tens of microsecond depending on the laser power and the focal-spot size. Parametric study has been performed to reveal the effect of laser pulse width, output power, ink concentration, and color on the bubble dynamics. The results show that the bubble generated by a laser pulse is largely similar to that produced by a thin-film heater. Consequently, the present work demonstrates the feasibility of developing a laser-actuated droplet generation mechanism for applications in ink-jet print heads. Furthermore, the results of this work indicate that the droplet generation frequency is likely to be further increased by optimizing the process parameters.

• Journal of Ginseng Research
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• v.47 no.4
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• pp.493-505
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• 2023

In recent years, an increasing number of reports have explored the wound healing mechanism of these two traditional Chinese herbal medicines- Panax ginseng and Panax notoginseng, but there is no systematic research on the related core functions and different mechanisms in the treatment of wound healing up to now. Based on network pharmacology and meta-analysis, the present work aimed to comprehensively review the commonality and diversity of P. ginseng and P. notoginseng in wound healing. In this study, a wound healing-related "ingredients-targets" network of two herbs was constructed. Thereafter, meta-analysis of the multiple target lists by Metascape showed that these two medicines significantly regulated blood vessel development, responses to cytokines and growth factors and oxygen levels, cell death, cell proliferation and differentiation, and cell adhesion. To better understand the discrepancy between these two herbs, it was found that common signaling pathways including Rap1, PI3K/AKT, MAPK, HIF-1 and Focal adhesion regulated the functions listed above. In parallel, the different pathways including renin-angiotensin system, RNA transport and circadian rhythm, autophagy, and the different metabolic pathways may also explained the discrepancies in the regulation of the above-mentioned functions, consistent with the Traditional Chinese Medicine theory about the effects of P. ginseng and P. notoginseng.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.3
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• pp.302-309
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• 2008

Epigenetic is usually referring to heritable traits that do not involve changes to the underlying DNA sequence. DNA methylation is known to serve as cellular memory. and is one of the most important mechanism of epigenetic. DNA methylation is a covalent modification in which the target molecules for methylation in mammalian DNA are cytosine bases in CpG dinucleotides. The 5' position of cytosine is methylated in a reaction catalyzed by DNA methyltransferases; DNMTl, DNMT3a, and DNMT3b. There are two different regions in the context of DNA methylation: CpG poor regions and CpG islands. The intergenic and the intronic region is considered to be CpG poor, and CpG islands are discrete CpG-rich regions which are often found in promoter regions. Normally, CpG poor regions are usually methylated whereas CpG islands are generally hypomethylated. DNA methylation is involved in various biological processes such as tissue-specific gene expression, genomic imprinting, and X chromosome inactivation. In general. cancer cells are characterized by global genomic hypomethylation and focal hypermethylation of CpG islands, which are generally unmethylated in normal cells. Gene silencing by CpG hypermethylation at the promotors of tumor suppressor genes is probably the most common mechanism of tumor suppressor inactivation in cancer.

• The Journal of Dong Guk Oriental Medicine
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• v.9
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• pp.95-110
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• 2000

The main purpose of this study is to lay the groundwork of mutual assistance between Shanghanlun and Sa-sang Constitutional Medicine by looking into their differences and similarities in the concept and the medical treatment in the diaphoretic therapy and the purgative therapy. The study compared Shanghan Jomun quoted in Soeumin. Dongyi-Soose-Bowon with Je-ma, Lee's Theory of Medicine. And its conclusion is the following: 1. Both Shanghanlun and Sa-sang Constitutional Medicine connote the concept of pathogenic factors in the Nae-Kyung Medicine as the medicinal substances. And both of them have the fundamental structure of exterior-to-interior movements in the symptoms of disease to appear when pathogenic factors penetrate into the bodies. 2. Sa-sang Constitutional Medicine has treated the causes and the mechanism of disease in the symptoms of disease differently from other therapies: focusing on the body's constitutional symptom of disease. namely Soeumin's lack of the Yang-Qi and the poor Ascending Yang, not an attack on pathogenic factors as a interior-exterior symptom. Therefore Ascending-yang Supplying Qi, which fills up the lacking parts of the body and keeps the balance of the body fitted in one's constitution, has been used rather than the diaphoretic and purgative therapy. 3. As Shanghanlun and Sa-sang Constitutional Medicine have the similarities in the interior-to-exterior structure, pathogenic factors. and the notion of diaphoresis and purgation, they do so in the principle of the medicinal substance and the therapy. However, there are actually differences of carrying out the diaphoretic and purgative therapy and other treatments between Shanghanlun and Sa-sang Constitutional Medicine by the reason of the dissimilarities in the mechanism of disease and focal points.

• Journal of Korean Neurosurgical Society
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• v.58 no.3
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• pp.167-174
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• 2015

Objective : This study investigates the role of a burr hole and calvarial bone marrow-derived stem cells (BMSCs) in a transient ischemic brain injury model in the rat and postulates a possible mechanism for the efficacy of multiple cranial burr hole (MCBH) surgery in moyamoya disease (MMD). Methods : Twenty Sprague-Dawley rats (250 g, male) were divided into four groups : normal control group (n=5), burr hole group (n=5), ischemia group (n=5), and ischemia+burr hole group (n=5). Focal ischemia was induced by the transient middle cerebral artery occlusion (MCAO). At one week after the ischemic injury, a 2 mm-sized cranial burr hole with small cortical incision was made on the ipsilateral (left) parietal area. Bromodeoxyuridine (BrdU, 50 mg/kg) was injected intraperitoneally, 2 times a day for 6 days after the burr hole trephination. At one week after the burr hole trephination, brains were harvested. Immunohistochemical stainings for BrdU, CD34, VEGF, and Doublecortin and Nestin were done. Results : In the ischemia+burr hole group, BrdU (+), CD34 (+), and Doublecortin (+) cells were found in the cortical incision site below the burr hole. A number of cells with Nestin (+) or VEGF (+) were found in the cerebral parenchyma around the cortical incision site. In the other groups, BrdU (+), CD34 (+), Doublecortin (+), and Nestin (+) cells were not detected in the corresponding area. These findings suggest that BrdU (+) and CD34 (+) cells are bone marrow-derived stem cells, which may be derived from the calvarial bone marrow through the burr hole. The existence of CD34 (+) and VEGF (+) cells indicates increased angiogenesis, while the existence of Doublecortin (+), Nestin (+) cells indicates increased neurogenesis. Conclusion : Based on these findings, the BMSCs through burr holes seem to play an important role for the therapeutic effect of the MCBH surgery in MMD.