• Molecules and Cells
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• v.37 no.12
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• pp.888-898
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• 2014

Pancreatic cancer is one of the most fatal cancers and is associated with limited diagnostic and therapeutic modalities. Currently, gemcitabine is the only effective drug and represents the preferred first-line treatment for chemotherapy. However, a high level of intrinsic or acquired resistance of pancreatic cancer to gemcitabine can contribute to the failure of gemcitabine treatment. To investigate the underlying molecular mechanisms for gemcitabine resistance in pancreatic cancer, we performed label-free quantification of protein expression in intrinsic gemcitabine-resistant and -sensitive human pancreatic adenocarcinoma cell lines using our improved proteomic strategy, combined with filter-aided sample preparation, single-shot liquid chromatography-mass spectrometry, enhanced spectral counting, and a statistical method based on a power law global error model. We identified 1931 proteins and quantified 787 differentially expressed proteins in the BxPC3, PANC-1, and HPDE cell lines. Bioinformatics analysis identified 15 epithelial to mesenchymal transition (EMT) markers and 13 EMT-related proteins that were closely associated with drug resistance were differentially expressed. Interestingly, 8 of these proteins were involved in glutathione and cysteine/methionine metabolism. These results suggest that proteins related to the EMT and glutathione metabolism play important roles in the development of intrinsic gemcitabine resistance by pancreatic cancer cell lines.

• Journal of the Korean GEO-environmental Society
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• v.13 no.9
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• pp.75-82
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• 2012

This paper is the results of analysis for the causes and characteristics of landslide according to heavy rain occurred in west area of Gangwon province which is affected by typhoon such as Ewiniar and Bilis in 2006. West side of Gangwon province is topographically weak for the landslide and debris flow since it is covered by soil of weathered rock such as Gneiss and Granite. From the results of analysis for the rainfall characteristics, it was found that landslide occurrence is closely related to the accumulated rainfall amount less than 3 days. Furthermore, it was found that regional difference of occurrence frequency is effected by 1-hour maximum rainfall intensity. From the results of analysis for the landslide data of 860 locations occurred in west side, it was shown that failure mode was changed from transition slide to liquidity slide. Occurrence frequency was high at the slope angle of $20{\sim}30^{\circ}$ slope length of 11~20, and slope width of 6~10. Landslide of west side is the typical landslide of Gneiss and Granite and the type of small scale which has narrow slope width.

• International Journal of Fluid Machinery and Systems
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• v.10 no.3
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• pp.287-295
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• 2017

The most detrimental pressure pulsations in high-head pump-turbines is caused by the rotor-stator interaction (RSI) between the guide vanes and runner blades. When the pump-turbine operates in the S-shaped region of the characteristic curves, the deteriorative flow structures may significantly strengthen RSI, causing larger pressure pulsations and stronger vibration with an increased risk of mechanical failure. CFD simulations were carried out to analyze the impacts of flow evolution on the pressure pulsations in the S-shaped region of a model pump-turbine. The results show that the reverse flow vortex structures (RFVS) at the runner inlet have regular development and transition patterns when discharge reduces from the best efficiency point (BEP). The RFVS first occur at the hub side, and then shift to the mid-span near the no-load point, which cause the strongest pressure pulsations. The locally distributed RFVS at hub side enhance the local RSI and makes the pressure fluctuations at the corresponding sections stronger than those at the rest sections along the spanwise direction. Under the condition of RFVS at the mid-span, the smaller flow rate make the smaller difference of pressure pulsation amplitudes in the spanwise direction. Moreover, the rotating stall, rotating at 35.7%-62.5% of the runner rotational frequency, make the low frequency components of pressure pulsations distribute unevenly along the circumference in the vaneless space. However, it have little influence on the distributions of high components.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.11
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• pp.1355-1360
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• 2013

A cracked solid propellant would have failure or fracture of rocket because of excessive combustion according to increase of burning area, therefore it is important to evaluate the fracture toughness of solid propellant. A procedure is used to investigate the material under a range of test temperatures between -60 and $60^{\circ}C$, three kind of specimen thickness, 4, 12.5 and 24.5 mm to determine the effect of two parameters on the fracture toughness. A center cracked tension (CCT) specimen is used in these tests, which were conducted using INSTRON 5567 testing machine and environmental chamber to evaluate the fracture toughness. The experimental results show that the fracture toughness tends to decreases with an increase in the temperature, and the effect of thickness indicates that the fracture toughness is highest at 12.5 mm under various temperatures except $-60^{\circ}C$. It is found that the fracture toughness of solid propellant is changed due to glass transition behavior around $-60^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.806-813
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• 2012

Adipocyte differentiation is strongly associated with obesity, which causes metabolic disorders. In this study, we investigated the inhibitory effects of widdrol on 3T3-L1 preadipocyte growth and differentiation. Widdrol decreased lipid droplet accumulation and down-regulated adipogenic transcription factors such as C/$EBP{\alpha}$, C/$EBP{\beta}$, and $PPAR{\gamma}$. Widdrol blocked preadipocyte proliferation and differentiation through the inhibition of mitotic clonal expansion, which was accompanied by the failure of degradation of p21, a cyclin-dependent kinase inhibitor. Cell-cycle analysis clearly indicated that widdrol actively induces cell-cycle arrest at the G1-S phage transition, causing cells to remain in the preadipocyte state. Moreover, widdrol increased p21 expression and inhibited Rb phosphorylation in preadipocyte incubated in a hormone medium. Therefore, these findings clearly suggest that widdrol blocks preadipocyte growth and differentiation through the inhibition of mitotic clonal expansion by p21-and Rb-dependent G1 arrest and can be developed as a potent anti-adipogenic agent for reducing obesity.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.8 no.3
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• pp.39-52
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• 2013

The main characteristic of technology commercialization by technology-intensive SMEs is that its success is highly uncertain due to the low maturities of their technology and market. Therefore, in order to find out more effective policy, it is essential to understand the technology commercialization in terms of the institutional support system including innovation policy, rather than an individual firm's strategy. Focusing on the Daeduk Innopolis, where many technology-intensive firms agglomerate, this paper explores SMEs' behavior for technology commercialization and the innovation system in the regional level. Then it points out the limitations and problems of the technology commercialization system in Daeduk innopolis, which might be closely related to the 'system failure' in the transition period. Based on the results of this innovation system approach, this paper also suggests some policy directions and agendas for overcoming those system failures in technology commercialization.

• Structural Engineering and Mechanics
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• v.22 no.2
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• pp.169-184
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• 2006

A close form solution of the maximum deflection for cracked columns with rectangular cross-sections was developed and thus the elastic buckling behavior and ultimate bearing capacity were studied analytically. First, taking into account the effect of the crack in the potential energy of elastic systems, a trigonometric series solution for the elastic deflection equation of an arbitrary crack position was derived by use of the Rayleigh-Ritz energy method and an analytical expression of the maximum deflection was obtained. By comparison with the rotational spring model (Okamura et al. 1969) and the equivalent stiffness method (Sinha et al. 2002), the advantages of the present solution are that there are few assumed conditions and the effect of axial compression on crack closure was considered. Second, based on the above solutions, the equilibrium paths of the elastic buckling were analytically described for cracked columns subjected to both axial and eccentric compressive load. Finally, as examples, the influence of crack depth, load eccentricity and column slenderness on the elastic buckling behavior was investigated in the case of a rectangular column with a single-edge crack. The relationship of the load capacity of the column with respect to crack depth and eccentricity or slenderness was also illustrated. The analytical and numerical results from the examples show that there are three kinds of collapse mechanisms for the various states of cracking, eccentricity and slenderness. These are the bifurcation for axial compression, the limit point instability for the condition of the deeper crack and lighter eccentricity and the fracture for higher eccentricity. As a result, the conception of critical transition eccentricity $(e/h)_c$, from limit-point buckling to fracture failure, was proposed and the critical values of $(e/h)_c$ were numerically determined for various eccentricities, crack depths and slenderness.

• KCI Concrete Journal
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• v.12 no.1
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• pp.57-68
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• 2000

The effect of structure size on the nominal strength of unidirectional fiber-polymer composites, failing by propagation of a kink band with fiber microbuckling, is analyzed experimentally and theoretically. Tests of novel geometrically similar carbon-PEEK specimens, with notches slanted so as to lead to a pure kink band (without shear or splitting cracks), are conducted. The specimens are rectangular strips of widths 15.875, 31.75. and 63.5 mm (0.625, 1.25 and 2.5 in and gage lengths 39.7, 79.375 and 158.75 mm (1.563, 3.125 and 6.25 in.). They reveal the existence of a strong (deterministic. non-statistical) size effect. The doubly logarithmic plot of the nominal strength (load divided by size and thickness) versus the characteristic size agrees with the approximate size effect law proposed for quasibrittle failures in 1983 by Bazant This law represents a gradual transition from a horizontal asymptote, representing the case of no size effect (characteristic of plasticity or strength criteria), to an asymptote of slope -1/2 (characteristic of linear elastic fracture mechanics. LEFM) . The size effect law for notched specimens permits easy identification of the fracture energy of the kink bandand the length of the fracture process zone at the front of the band solely from the measurements of maximum loads. Optimum fits of the test results by the size effect law are obtained, and the size effect law parameters are then used to identify the material fracture characteristics, Particularly the fracture energy and the effective length of the fracture process zone. The results suggest that composite size effect must be considered in strengthening existing concrete structural members such as bridge columns and beams using a composite retrofitting technique.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.2B
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• pp.108-117
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• 2007

Recursive DNS is configured as primary or secondary DNS on user PC and performs domain name resolution corresponding user's DNS query. At present, the amount of DNS traffic is occupied high rate in the total internet traffic and the internet traffic would be increased by failure of IPv6 DNS queries and responses as IPv6 transition environment. Also, existing Recursive DNS service mechanisms is unstable on malicious user's attack same as DoS/DDoS Attack and isn't provide to user trust DNS service fail-over. In this paper, we propose IPv6 Recursive DNS service mechanisms for based on anycast for improving stability. It is that fail-over Recursive DNS is configured IPv6 Anycast address for primary Recursive DNS's foil-over. this mechanisms increases reliability and resiliency to DoS/DDoS attacks and reduces query latency and helps minimize DNS traffic as inducing IPv6 address.

• Journal of Information Technology and Architecture
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• v.9 no.4
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• pp.443-453
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• 2012

In order to minimize the damage from system failures, systems over various fields are requested to contain the safety-critical features. In this paper, we deliver the considerable issues, especially, in the cyber physical systems that is recently used as a safety-critical system, as well as we propose the model driven architecture based on time as its the important factor. Based on meta-modeling approach, we introduce the time-based architecture which is associated with deadline, transition state, and threshold, and also we work out a design for this by using model driven architecture. We propose a realizable safety-critical architecture by means of showing failure handling components with safety transaction model from the meta-model. In the detailed models and the example, we design a basic safety processing state, a multiple safety processing state, and a compound safety processing state for completing the safety-critical system architecture.