• Journal of Microbiology and Biotechnology
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• v.33 no.9
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• pp.1206-1212
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• 2023

The Wnt/β-catenin pathway plays essential roles in regulating various cellular behaviors, including proliferation, survival, and differentiation [1-3]. The intracellular β-catenin level, which is regulated by a proteasomal degradation pathway, is critical to Wnt/β-catenin pathway control [4]. Normally, casein kinase 1 (CK1) and glycogen synthase kinase-3β (GSK-3β), which form a complex with the scaffolding protein Axin and the tumor suppressor protein adenomatous polyposis coli (APC), phosphorylate β-catenin at Ser45, Thr41, Ser37, and Ser33 [5, 6]. Phosphorylated β-catenin is ubiquitinated by the β-transducin repeat-containing protein (β-TrCP), an F-box E3 ubiquitin ligase complex, and ubiquitinated β-catenin is degraded via a proteasome pathway [7, 8]. Colorectal cancer is a significant cause of cancer-related deaths worldwide. Abnormal up-regulation of the Wnt/β-catenin pathway is a major pathological event in intestinal epithelial cells during human colorectal cancer oncogenesis [9]. Genetic mutations in the APC gene are observed in familial adenomatous polyposis coli (FAP) and sporadic colorectal cancers [10]. In addition, mutations in the N-terminal phosphorylation motif of the β-catenin gene were found in patients with colorectal cancer [11]. These mutations cause β-catenin to accumulate in the nucleus, where it forms complexes with transcription factors of the T-cell factor/lymphocyte enhancer factor (TCF/LEF) family to stimulate the expression of β-catenin responsive genes, such as c-Myc and cyclin D1, which leads to colorectal tumorigenesis [12-14]. Therefore, downregulating β-catenin response transcription (CRT) is a potential strategy for preventing and treating colorectal cancer. Plant cytokinins are N⁶-substituted purine derivatives; they promote cell division in plants and regulate developmental pathways. Natural cytokinins are classified as isoprenoid (isopentenyladenine, zeatin, and dihydrozeatin), aromatic (benzyladenine, topolin, and methoxytopolin), or furfural (kinetin and kinetin riboside), depending on their structure [15, 16]. Kinetin riboside was identified in coconut water and is a naturally produced cytokinin that induces apoptosis and exhibits antiproliferative activity in several human cancer cell lines [17]. However, little attention has been paid to kinetin riboside's mode of action. In this study, we show that kinetin riboside exerts its cytotoxic activity against colon cancer cells by suppressing the Wnt/β-catenin pathway and promoting intracellular β-catenin degradation.

• Fibers and Polymers
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• v.2 no.3
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• pp.129-134
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• 2001

Liquid crystalline (LC) poly(ethylene terephthalate-co-2(3)-chloro-1,4-phenylene terephthalate) (50/50, mole/mole) [PECPT] was synthesized and blended with polycarbonate (PC). LC properties of PECPT and thermal, morphological, and rheological behaviors of the PECPT/PC blend were studied. PECPT showed the nematic LC phase and much longer relaxation time than poly(ethylene terephthalate) (PET). The apparent melt viscosity of PECPT was one third of that of FET. An abrupt torque change was observed during the blending process due to the orientation of LC domains. For the blends containing 10~30 wt% of PECPT, the complex viscosities were higher than that of PC. As PECPT content increases above 40 wt%, shear thinning was observed. The lowest complex viscosity was obtained at 40~50 wt%. Transesterification of PECPT and PC was confirmed by the selective chemical degradation of carbonate groups in PC.

• Molecules and Cells
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• v.24 no.3
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• pp.307-315
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• 2007

Gene regulation is a fundamental process in biological systems, where transcription factors (TFs) play crucial roles. Inferring transcriptional interactions between TFs and their target genes has utmost importance for understanding the complex regulatory mechanisms in cellular systems. On one hand, with the rapid progress of various high-throughput experiment techniques, more and more biological data become available, which makes it possible to quantitatively study gene regulation in a systematic manner. On the other hand, transcription regulation is a complex biological process mediated by many events such as post-translational modifications, degradation, and competitive binding of multiple TFs. In this review, with a particular emphasis on computational methods, we report the recent advances of the research topics related to transcriptional regulatory networks, including how to infer transcriptional interactions, reveal combinatorial regulation mechanisms, and reconstruct TF activity profiles.

• Corrosion Science and Technology
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• v.12 no.2
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• pp.79-84
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• 2013

In general, pipelines at nuclear power plants are affected by various types of degradation mechanisms and may be ruptured after gradually thinning. FAC (Flow-Accelerated Corrosion) is typical aging mechanism affecting the secondary side piping system. In Korea nuclear power plants, CHECWORKS program have been used for management of wall thinning damages. However, sometimes, CHECWORKS program shows wrong results at the stage of NFA (Network Flow Analysis) in case of complex pipelines. This paper describes the calculation results of pressure drop in a complex pipeline and single line by using the CHECWORKS program and the analysis results are compared with those of engineering calculation results including errors between them.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1018-1023
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• 2006

The metal chelate complex of aluminum 8-hydroxyquinolines $(Alq_3)$ is an important electro-luminescent (EL) material used in fabricating organic light emitting (OLEDs). In this work, diodes / displays using in house synthesized $Alq_3$ and simple structure have been fabricated. It is demonstrated that luminance of $12460\;cd/m^2$ and efficiency of 3.1 cd/A are achievable in these fluorescent devices. Possible degradation effects are analyzed.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.1
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• pp.67-73
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• 2005

In order to compensate for the degradation caused by the frequency shift under the Rayleigh fading with the balanced QPSK DS-SS communication, it is necessary to devise an efficient phase estimation method. In this paper, using the pilot signal, three conventional methods and a complex number method are presented and compared. The performance comparison results show that the combination complex number method is better than the other conventional methods, which have some limiting conditions.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.147-150
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• 2014

Copper ink has been prepared by mixing copper(II) formate and 2-ethyl-1-hexylammonium bicarbonate (EHABC) to overcome some weak points such as aggregation and degradation of copper nano-type ink. Ink was coated on glass substrate and calcined at $110^{\circ}C$ to $150^{\circ}C$ to generate electrically conductive copper film under two different atmospheres such as nitrogen gas and gaseous mixture of formic acid and methanol. The lowest resistivity of $1.88{\mu}{\Omega}{\cdot}cm$ of copper film was obtained at $150^{\circ}C$ in gaseous formic acid condition. The long-term resistivity shows to increase from $1.88{\mu}{\Omega}{\cdot}cm$ to $2.61{\mu}{\Omega}{\cdot}cm$ after one month.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.12
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• pp.847-852
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• 2016

Using both EVA and POE encapsulants, we fabricated polycrystalline Si PV modules and performed a set of reliability tests of PID, DH, TC, and Complex prior to outdoor installation. The power output with temperatures and insolation as well as I-V characteristics had been monitored under outdoor environments for 18 months. In the entire period, the total power of 3,576 kWh from POE PV modules was observed larger than 3,449 kWh from EVA PV modules by 3.5%. All the PV modules showed a 5.6~9.2% drop in the conversion efficiency. As for the solar power generation, the PV modules performed through PID, TC test revealed distinct difference in between EVA and POE for which the POE PV module produced more power by +11.4% and +6.6%, respectively, as measured in the 18th month. In addition, POE was proved to protect better the solar cells under PID influence.

• Journal of Plant Biology
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• v.39 no.4
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• pp.301-307
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• 1996

The disassembly of Chl-protein complexes during dark-induced senescence (DIS) was investigated using detached third and fourthleaves of 21$\pm$1 day-old Arabidopsis thaliana. Although Chl content decreased linearly after 1 d, a significant decrease of photochemical effeciency (Fv/Fm) was observed after 2 d. In experiments using native green gel electrophoresis of Chl-protein complexes combined with additional two-dimensional SDS-PAGE analysis, we could observe the degradation of both photosystems after 2 d. Although light-harvesting complex(LHC) for PSI (LHCI) was degraded first in PSI complex, small PSII apoproteins including CP47/CP43 and D1/D2 apoproteins were degraded first in PSII complexes. LHC for PSII (LHCII) trimers were stable until 4 d. The level of LHCII monomers was increased until 3 and decreased thereafter, resulting in the increase of free pigments. These results suggest that the disassembly process of PSI is different from that of PSII.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.107-108
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• 2022

This study aims to solve environmental problems by reducing complex degradation and recycling industrial waste by utilizing waste fibers and blast furnace slags, which are industrial by-products. In addition, it is intended to secure long-term durability to reduce cracks. To this end, the disadvantages of fiber-reinforced concrete are to solve the problem of lowering liquidity and ensuring curing time, and to find the optimal combination when waste fibers and blast furnace slag are used together.