• BMB Reports
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• v.52 no.8
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• pp.490-495
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• 2019

Using tunneling nanotubes (TNTs), various pathological molecules and viruses disseminate to adjacent cells intercellularly. Here, we show that the intracellular invasion of Mycoplasma hyorhinis induces the formation of actin- and tubulin-based TNTs in various mammalian cell lines. M. hyorhinis was found in TNTs generated by M. hyorhinis infection in NIH3T3 cells. Because mycoplasma-free recipient cells received mycoplasmas from M. hyorhinis-infected donor cells in a mixed co-culture system and not a spatially separated co-culture system, direct cell-to-cell contact via TNTs was necessary for the intracellular dissemination of M. hyorhinis. The activity of Rac1, which is a small GTP binding protein, was increased by the intracellular invasion of M. hyorhinis, and its pharmacological and genetic inhibition prevented M. hyorhinis infection-induced TNT generation in NIH3T3 cells. The pharmacological and genetic inhibition of Rac1 also reduced the cell-to-cell dissemination of M. hyorhinis. Based on these data, we conclude that intracellular invasion of M. hyorhinis induces the formation of TNTs, which are used for the cell-to-cell dissemination of M. hyorhinis.

• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.6-13
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• 2021

Cases and studies on the selection method of CTQ are relatively active, but there are few cases or studies on the selection method of CTP which is important in the device industry. In fact, many companies simply select and manage CTP from the point of contact based on their experience and intuition. The purpose of this study is to present an evaluation model and a mathematical decision model for rational and systematic CTP selection to improve the process quality of semiconductor equipment lines. In the evaluation model, AHP (Analytic Hierarchy Process) analysis technique was applied to show objective and quantitative figures, and Fuzzy decision-making model was used to solve the ambiguity and uncertainty in the decision-making process. Decision Value (DV) was presented. The subjects were 22 process factors managed in the Plating Process that the representative equipment line can do. As a result, the evaluation model proposed in this study can support more efficient and effective decision-making for process quality improvement by more objectively measuring the problem of subjective CTP selection in manufacturing sites.

• The Journal of Korean Academy of Prosthodontics
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• v.25 no.1
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• pp.137-154
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• 1987

The purpose of this investigation was to determine the surface characteristics and the fittness of the resilienct denture lines. Firstly, 50 samples ($2.0{\times}4.0{\times}0.3cm$) of 4 resilient lining materials (Molloplast B, Coe Super Soft, Mollosil, Coe Soft) and one conventional acrylic resin (K-33) were processed according to manufacture's direction and examined the surface characteristics by use of surface profilometer and scanning electron microscopy. Secondly, 50 identical maxillary casts were made and 50 denture bases were pro cessed of 4 resilient liners and one conventional acrylic resin and they were stored in the room temperature water bath of 1 day, 1 week, 2 weeks, 3 weeks, 4 weeks and 6 weeks after processing. The original casts were cut away 1 cm from the posterior border, the dentures were seated, and the existing space was measured at seven regions according to the storage time by use of the modified thickness guage. The results were as follows. 1. Surface roughness (Rz) were $4.00{\pm}1.60{\mu}m$ in Mollosil, $4.47{\pm}2.21{\mu}m$ in Molloplast B, $7.46{\pm}1.70{\mu}m$ in Coe Super Soft, $12.70{\pm}2.39{\mu}m$ in Coe Soft and $13.03{\pm}2.74{\mu}m$ in K-33. 2. The generation of porosity was far more active in cold-cured resilient liners (Coe Soft and Mollosil) than in heat cured resilient liners (Molloplast B, and Coe Super Soft) and conventional heat cured resin (K-33). 3. Denture bases showed the greatest discrepancy at the central portion of the posterior palatal border and the intimate contact in the buccal flange regardless of denture base materials. 4. When the denture bases were stored in the water for 1 day and 6 weeks after processing, the sum of average discrepancies in the seven regions of the denture base was the greatest in K-33 followed by Molloplast B, Mollosil, Coe Soft and Coe Super Soft but followed by Coe Soft, Molloplast B, Mollosil, Coe Super Soft in that order respectively. 5. There was not a significant difference (p>0.05) in Coe Super Soft, K-33 but there was a significant difference (P<0.01) in Molloplast B, Mollosil, Coe Soft at the amount of dimensional changes according to the storage time.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.943-948
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• 2021

The purpose of this study was to investigate changes in surface dose due to increased scattering of gamma rays from patients injected with ^99mTc and ¹⁸F, which are radioactive isotopes, in close contact with materials with high atomic number such as the walls of the stable room. Prepare ^99mTc and ¹⁸F by injecting 20 and 10 mCi respectively into the NEMA phantom, and then measuring the surface dose for 60 minutes by positioning the phantom at a height of 1 m above the surface, at a distance of 0, 5 and 10 cm from the wall, and at the same location as the phantom facing the wall. Each experiment was repeated five times for reproducibility of the experiment and one way analysis of variability (ANOVA) was performed for significance testing and Tukey was used as a post-test. The study found that surface doses of 220.268, 287.121, 243.957, and 226.272 mGy were measured at ^99mTc, respectively, in the case of empty space and in the case of 0, 5 and 10 cm, while those of ¹⁸F were measured at 637.111, 724.469, 657.107, and 640.365 mGy, respectively. In order to reduce changes in surface dose depending on the patient's location while waiting, it is necessary to keep the distance from the ground or the wall where the patient is closely adhered to, or install an air mattress, etc., to prevent the scattered lines as much as possible, considering the scattered lines due to the wall etc. in future setup of the patient waiting room and safety room, and in addition to the examination, the external skin width may be reduced.

• Korean Journal of Ornithology
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• v.25 no.2
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• pp.94-100
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• 2018

Bird electrocution on contact with electricity lines is well reported and is quite common in Mongolian open areas. We visited 15-kV electricity distribution pole lines in a Southern Mongolian semi-desert region three times in 2017, in April, July, and September, to assess their risks to birds. The carcasses of 45 electrocuted birds representing 12 species were identified from 250 poles (overall mortality rate of 1.12% every 10 km). The majority of these electrocuted birds were endangered Saker Falcon (n=11) and common Black Kite (n=11). The lacks of roosting or perching sites in our study sites (indeed other open areas in Mongolia) may resulted for such high rate bird electrocution. A 751-base pair (bp) cytochrome c oxidase I (COI) gene was amplified for DNA sequence-based identification of carcasses that were difficult to identify directly. Our findings revealed the high electrocution risk for birds in Mongolian open areas, especially for the birds of prey, with relatively low-efficiency electrocution mitigation approaches. The findings also indicate that there is a need for better understanding of the risk of bird electrocution, particularly in the open areas. This will contribute to the conservation of endangered species.

• Journal of Biomedical Engineering Research
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• v.23 no.3
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• pp.171-179
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• 2002

It is well known that the geometry of the articular surface plays a major role in the kinematic and kinetic analysis to understand human knee joint function during motion. The functionality of the knee joint cannot be accurately modeled without considering the effects of sliding and lolling motions. We Present a 3-D human knee joint model considering sliding and rotting motion and major ligaments. We employ more realistic articular geometry using two cam profiles obtained from the extrusion of the sagittal Plain view of the representative Computerized Tomography image of the knee joint compared to the previously reported model. Our model shows good agreement with the already reported experimental results on Prediction of the lines of force through the human joint during gait. The contact point between femur and tibia moves toward the Posterior direction as the knee undergoes flexion, reflecting the coupling of anterior and Posterior motion with flexion/extension. The anterior/posterior displacement of the contact Point on the tibia plateau during one gait cycle is about 16 mm. for the lateral condyle and 25 mm. for the medial condyle using the employed model Also. the femur motion on the tibia undergoes lateral/medial movement about 7 mm. and 10 mm. during one gait cycle for the lateral condyle and medial condyle. respectively. The developed computational model maybe Potentially employed to identify the joint degeneration.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.355-363
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• 2015

HVDC technology has become popular as an economic mode of bulk power transmission over very long distances. Polymeric insulators in HVDC power transmission lines are affected by surface tracking and erosion problems due to contamination deposit, which pose a greater challenge in maintaining the reliability of the HVDC system. In addition, polymeric insulators are also naturally affected by aging due to various environmental stresses, which in turn accelerates the surface tracking and erosion problems. Research works towards the improvement of tracking and erosion resistance of polymeric insulators by adding nano-sized fillers in the base material are being carried out worldwide. However, surface tracking and erosion performance of nano-filled aged polymeric insulators for HVDC applications are not well reported. Hence, in the present work, tracking and erosion resistance of the nano $Al(OH)_3$ filled silicone rubber insulation material has been evaluated under DC voltages at different filler concentrations and aged conditions, as per IEC 60587 test procedures. Leakage current and contact angle measurements were carried out to understand the surface hydrophobicity. Moving average technique was used to analyze the trend followed by leakage current. Water aged specimen shows less tracking resistance when compared with thermal aged specimen. It is observed that nano-filler concentration of 5% is even sufficient to get better tracking/erosion resistance under DC voltages.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.3
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• pp.383-389
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• 2016

Kissing of sub-conductors due to magnetic forces has been investigated in a 154 kV bundled overhead transmission line. With increasing ampacity of the conductors and enlarging the distance between spacers, lager magnetic force was measured. When the phase ampacity was 2,000 amps and the distance between two adjacent spacers was 68 m, for instance, the conductors became unstable and vibrated with a frequency of several herts. Furthermore, when the ampacity was 2,250 amps and the distance between spacers was 136 m, the two sub-conductors were contacted. Analysing the magnetic forces with distance of spacers, the safe distance of spacers to avoid contact of sub-conductors was presented. The change of the safe distance is discussed due to various parameters, such as residual stresses and wind pressures, in the real transmission lines.

• Journal of the Korean Society for Railway
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• v.19 no.6
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• pp.792-801
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• 2016

Standard Penetration Test (SPT) and Cone Penetration Test (CPT) are widely used in geotechnical investigation methods for railway roadbed. However, SPT can not be used on the Railway track, since the equipment may contact to the electric lines. However, a portable equipment can be used for geotechnical investigation without electrical hazard. Dynamic Cone Penetrometer (DCP) is one of representative portable equipments. A normal portable DCP has usually not enough driving energy and the rigidity of cone-rod, so it is impossible to investigate the required investigate penetration depth. In this study, The adaptability of Pagani cone test which is one of portable dynamic cone penetrometer is studied and compared with SPT-N data. As a result of this study, the proposed correlation factors between Pagani cone test and SPT-N values after corrections is 1.48 for sandy soil and 1.33 for clayey soil.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.1
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• pp.183-198
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• 1998

This study was designed to investigate the peri-implant tissue reaction in ovariectomized osteoporotic female rats, and to evaluate effects of estrogen, calcitonin, parathyroid hormone on the bone - implant interface in osteoporotic rats. 120 Sprague - Dawley rats were used in this experiments. Osteoporosis was induced by bilateral ovariectomy. They were divided 5 groups : sham-operated control group(Sham), ovariectomized group (OVX), OVX and estrogen treated group (OVX+E), OVX and PTH treated group (OVX+PTH), and OVX and calcitonin treated group (OVX+CT). Eight weeks after ovariectomy, two titanium screw implants were inserted into the left tibia of each rat. Eight weeks after the insertion of the implants, the periotest values (PTV) of implant were examined, and the rats were sacrificed, and examined the reaction of bone tissue surrounding the implant both histologically and histomorphometrically. The bone density and ash weight of opposite right tibia were examined. Over 40 rats were fractured on left tibia that was implant inserted. On histologically finding, all groups were osseointegrated well, especially in OVX+PTH group. In OVX group, tibial cortical bone showed many large harversian canal and microfracture lines. The OVX+PTH group showed the lowest mean PTV (-2.33) (p<0.05), and the hightest mean bone - implant contact percentage (89%) (p>0.05). But the OVX+CT group showed the highest mean bone density ($5.45mg/cm^3$) and ash weight (56.12%) (p<0.05). The results indicate that PTH treatment enhances osseointegration of implant in OVX rats, and CT treatment depresses bone turnover and prevent the development of osteopenia in OVX rats.