• The Korean Journal of Physiology and Pharmacology
• /
• v.18 no.1
• /
• pp.61-66
• /
• 2014

Lung cancer is still the number one cause of death from cancer worldwide. The clinical effect of platinum-based chemotherapy for non-small cell lung cancer is constrained by the resistance to drug. To overcome chemo-resistance, various modified treatment including combination therapy has been used, but overall survival has not been improved yet. In this study, chemo-resistant lung cancer cells, A549/Cis and H460/Cis, were developed by long-term exposure of cells to cisplatin and the proliferative capability of these resistant cells was verified to be reduced. We found cytotoxic effect of epigallocatechin gallate (EGCG), a major catechin derived from green tea, on both the parental lung cancer cells, A549 and H460, and their cisplatin resistant cells, A549/Cis and H460/Cis. ELISA and Western blot analysis revealed that EGCG was able to increase interlukine-6 (IL-6) production per cell, whereas its downstream effector Signal transducers and activators of transcription 3 (STAT3) phosphorylation was not changed by EGCG, indicating that IL-6/STAT3 axis is not the critical signaling to be inhibited by EGCG. We next found that EGCG suppresses the expression of both Axl and Tyro 3 receptor tyrosine kinases at mRNA and protein level, explaining the cytotoxic effect of EGCG on lung cancer cells, especially, regardless of cisplatin resistance. Taken together, these data suggest that EGCG impedes proliferation of lung cancer cells including their chemo-resistant variants through downregulation of Axl and Tyro 3 expression.

• Journal of Biomedical Engineering Research
• /
• v.33 no.4
• /
• pp.169-176
• /
• 2012

Tumor cell morphology is closely related to its migratory behaviors. An active tumor cell has a highly irregular shape, whereas a spherical cell is inactive. Thus, quantitative analysis of cell features is crucial to determine tumor malignancy or to test the efficacy of anticancer treatment. We use 3D time-lapse phase-contrast microscopy to analyze single cell morphology because it enables to observe long-term activity of living cells without photobleaching and phototoxicity, which is common in other fluorescence-labeled microscopy. Despite this advantage, there are image-level drawbacks to phase-contrast microscopy, such as local light effect and contrast interference ring. Therefore, we first corrected for non-uniform illumination artifacts and then we use intensity distribution information to detect cell boundary. In phase contrast microscopy image, cell is normally appeared as dark region surrounded by bright halo ring. Due to halo artifact is minimal around the cell body and has non-symmetric diffusion pattern, we calculate cross sectional plane which intersects center of each cell and orthogonal to first principal axis. Then, we extract dark cell region by analyzing intensity profile curve considering local bright peak as halo area. Finally, we calculated the Fourier descriptor that morphological characteristics of cell to classify tumor cells into active and inactive groups. We validated classification accuracy by comparing our findings with manually obtained results.

• KIISE Transactions on Computing Practices
• /
• v.22 no.11
• /
• pp.614-618
• /
• 2016

As information on the internet and the data from smart devices are growing, the amount of stream data is also increasing in the real world. The stream data, which is a potentially large data, requires online learnable models and algorithms. In this paper, we propose a novel class of models: predictive convolutional neural networks to be able to perform online learning. These models are designed to deal with longer patterns as the layers become higher due to layering convolutional operations: detection and max-pooling on the time axis. As a preliminary check of the concept, we chose two-month gathered GPS data sequence as an observation sequence. On learning them with the proposed method, we compared the original sequence and the regenerated sequence from the abstract information of the models. The result shows that the models can encode long-range patterns, and can generate a raw observation sequence within a low error.

• The korean journal of orthodontics
• /
• v.42 no.1
• /
• pp.39-46
• /
• 2012

Objective: We evaluated the detachment force, amount of deformation, fracture mode, and pull-out force of 3 different wires used for bonded lingual retainer fabrication. Methods: We tested 0.0215-inch five-stranded wire (PentaOne, Masel; group I), $0.016{\times}0.022$-inch dead-soft eight-braided wire (Bond-A-Braid, Reliance; group II), and 0.0195-inch dead-soft coaxial wire (Respond, Ormco; group III). To test detachment force, deformation, and fracture mode, we embedded 94 lower incisor teeth in acrylic blocks in pairs. Retainer wires were bonded to the teeth and vertically directed force was applied to the wire. To test pull-out force, wires were embedded in composite that was placed in a hole at the center of an acrylic block. Tensile force was applied along the long axis of the wire. Results: Detachment force and mode of fracture were not different between groups. Deformation was significantly higher in groups II and III than in group I (p < 0.001). Mean pull-out force was significantly higher for group I compared to groups II and III (p < 0.001). Conclusions: Detachment force and fracture mode were similar for all wires, but greater deformations were seen in dead-soft wires. Wire pull-out force was significantly higher for five-stranded coaxial wire than for the other wires tested. Five-stranded coaxial wires are suggested for use in bonded lingual retainers.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.39 no.1
• /
• pp.21-26
• /
• 2013

Objectives: Full thickness skin grafts (FTSG) offer several advantages; they are esthetically superb, have less postoperative shrinkage, and offer minimal postoperative pain and scar formation at the donor site. As a donor site of FTSG, the groin offers a relatively large area of skin with high elasticity. The aim of this study was to evaluate FTSG from the groin for reconstruction in oral and maxillofacial surgery. Materials and Methods: In a retrospective study, 50 patients (27 males, 23 females) who received FTSG from the groin were evaluated for their operation records, clinical photography, and medical records. Results: The width of skin from the groin was distributed from 2-8 cm (mean: 5.1 cm) at the donor site, while the long axis length was distributed from 3-13 cm (mean: 7.4 cm). A high number of patients, 47 patients (94%) out of 50, showed good healing at the donor site. Wound impairment was seen in 3 patients (6%), minor wound dehiscence in 2 patients, and severe wound dehiscence in 1 patient. In the recipient site, delayed healing was observed in 2 patients (4%). Conclusion: FTSG from the groin to repair soft tissue defects in reconstruction surgery is a good method due to the relatively big size of the graft, decreasing morbidity at the donor site, and higher graft survival rates.

• Structural Engineering and Mechanics
• /
• v.20 no.5
• /
• pp.543-558
• /
• 2005

The natural frequencies of a long span bridge vary during its construction and it is thus difficult to apply traditional tuned liquid column dampers (TLCD) with a fixed configuration to reduce bridge vibration. The restriction of TLCD imposed by frequency tuning requirement also make it difficult to be applied to structure with either very low or high natural frequency. A semi-active tuned liquid column damper (SATLCD), whose natural frequency can be altered by active control of liquid column pressure, is studied in this paper. The principle of SATLCD with adaptive tuning capacity is first introduced. The analytical models are then developed for lateral vibration of a structure with SATLCD and torsional vibration of a structure with SATLCD, respectively, under either harmonic or white noise excitation. The non-linear damping property of SATLCD is linearized by an equivalent linearization technique. Extensive parametric studies are finally carried out in the frequency domain to find the beneficial parameters by which the maximum vibration reduction can be achieved. The key parameters investigated include the distance from the centre line of SATLCD to the rotational axis of a structure, the ratio of horizontal length to the total length of liquid column, head loss coefficient, and frequency offset ratio. The investigations demonstrate that SATLCD can provide a greater flexibility for its application in practice and achieve a high degree of vibration reduction. The sensitivity of SATLCD to the frequency offset between the damper and structure can be improved by adapting its frequency precisely to the measured structural frequency.

• The Journal of Advanced Prosthodontics
• /
• v.5 no.4
• /
• pp.457-463
• /
• 2013

PURPOSE. The purpose of this study was to compare the effect of a diode laser and traditional irrigants on the bond strength of self-adhesive cement. MATERIALS AND METHODS. Fifty-five incisors extracted due to periodontal problems were used. All teeth were instrumented using a set of rotary root canal instruments. The post spaces were enlarged for a No.14 (diameter, 1.4 mm) Snowlight (Abrasive technology, OH, USA) glass fiber reinforced composite post with matching drill. The teeth were randomly divided into 5 experimental groups of 11 teeth each. The post spaces were treated with the followings: Group 1: 5 mL 0.9% physiological saline; Group 2: 5 mL 5.25% sodium hypochlorite; Group 3: 5 mL 17% ethylene diamine tetra acetic acid (EDTA), Group 4: 37% orthophosphoric acid and Group 5: Photodynamic diode laser irradiation for 1 minute after application of light-active dye solution. Snowlight posts were luted with self-adhesive resin cement. Each root was sectioned perpendicular to its long axis to create 1 mm thick specimens. The push-out bond strength test method was used to measure bond strength. One tooth from each group was processed for scanning electron microscopic analysis. RESULTS. Bond strength values were as follow: Group 1 = 4.15 MPa; Group 2 = 3.00 MPa; Group 3 = 4.45 MPa; Group 4 = 6.96 MPa; and Group 5 = 8.93 MPa. These values were analysed using one-way ANOVA and Tukey honestly significant difference test (P<.05). Significantly higher bond strength values were obtained with the diode laser and orthophosphoric acid (P<.05). There were no differences found between the other groups (P> .05). CONCLUSION. Orthophosphoric acid and EDTA were more effective methods for removing the smear layer than the diode laser. However, the diode laser and orthophosphoric acid were more effective at the cement dentin interface than the EDTA, Therefore, modifying the smear layer may be more effective when a self-adhesive system is used.

• The Bulletin of The Korean Astronomical Society
• /
• v.41 no.2
• /
• pp.48.2-48.2
• /
• 2016

The wide-field and the round-the clock operation capabilities of the KMTNet enables the discovery, astrometry and follow-up physical characterization of asteroids and comets in a most efficient way. We collectively refer to the team members, partner organizations, the dedicated software subsystem, the computing facility and research activities as Deep Ecliptic Patrol of the Southern Sky (DEEP-South). Most of the telescope time for DEEP-South is devoted to targeted photometry of Near Earth Asteroids (NEAs) to push up the number of the population with known physical properties from several percent to several dozens of percent, in the long run. We primarily adopt Johnson R-band for lightcurve study, while we employ BVI filters for taxonomic classification and detection of any possible color variations of an object at the same time. In this presentation, the progress and new findings since the last KAS meeting will be outlined. We report DEEP-South preliminary lightcurves of several dozens of NEAs obtained at three KMTNet stations during the first year runs. We also present a physical model of asteroid (5247) Krylov, the very first Non principal Axis (NPA) rotator that has been confirmed in the main belt (MB). A new asteroid taxonomic classification scheme will be introduced with an emphasis on its utility in the LSST era. The progress on the current version of automated mover detection software will also be summarized.

• Archives of Craniofacial Surgery
• /
• v.18 no.1
• /
• pp.16-20
• /
• 2017

Background: Pyogenic granuloma (PG) is a benign vascular lesion of the mucosa and skin. Recent studies of the epidemiology of PG are rare. We aimed to retrospectively analyze characteristics of PG cases in South Korea. Methods: We reviewed the medical records of 155 patients treated for PG between March 2005 and May 2014. The male-to-female ratio was 1:1.2 (70 males, 85 females). The mean age of patients was 35.3 years. Results: A high occurrence was observed in the first and third decades in males, and the fourth to fifth decades in females. There was a statistically significant difference between genders according to age group (p<0.05). The average lesion diameter was $0.84{\pm}0.46cm$ (long axis). The most frequently involved site was the face (n=47). Bleeding was the primary complication (n=41). PG was mostly treated with excisional biopsy (n=74). The recurrence rate was 7.7% (n=12). Conclusion: We concluded that most common site of PG was the face, the age of female with PG is higher than previous studies, and finger is associated with trauma more than other sites. The most recent epidemiological information on PG of this study will support the treatment and diagnosis of PG and future research objectives.

• International Commerce and Information Review
• /
• v.11 no.1
• /
• pp.441-463
• /
• 2009

FTA is acting as a central axis to accomplish the worldwide trade liberalization as FTA has been globally spreading with competition. As the global economic depression and the trend of new protectionism are getting grave, and the trade liberalization of GATT and WTO is getting delayed, FTA is spread as an alternative. FTA is often called as RTA: Regional Trade Agreement(regional free trade agreement) which takes place mainly around the neighbor nations or regular districts, and these days, it is tending towards agreements between long distant nations, so, it's not limited to the regular districts. Among the FTA agreement items, in addition to the customs abolition, the opening and investment liberalization of service market like finance, communication etc., intellectual property rights are included in the government's target range. Korea also is actively proceeding FTA conclusion. Korean government has concluded the agreements with Singapore, european nations beginning from Chile concluded in 2003, and is proceeding more the negotiations with Japan, Canada, Mexico, India etc. Now in 2009, FTA of Korea-United States is actually waiting for just the passage of assembly ratification. But, if FTA becomes effective, because our domestic market should be entirely opened, it is expected that the blow against our domestic agricultural field which is weak, compared with that of the United States, a nation of worldwide agricultural products, is not an ordinary one. According to it, we need a whole plan to cope with, so, the purpose of this study is to suggest the strategy by comparing and analysing the Korean agricultural competitive power, and to find the other development stratagem.