• BMB Reports
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• 제41권5호
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• pp.358-362
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• 2008

RNA interference (RNAi) is the process of sequence-specific gene silencing. However, RNAi efficiency still needs to be improved for effective inhibition of target genes. We have developed an effective strategy to express multiple shRNAs (small hairpin RNA) simultaneously using multiple RNA Polymerase III (Pol III) promoters in a single vector. Our data demonstrate that multiple shRNAs expressed from Pol III promoters have a synergistic effect in repressing the target gene. Silencing of endogenous cyclophilin A (CypA) or key HIV viral genes by multiple shRNAs results in significant inhibition of the target gene.

• Animal cells and systems
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• 제2권2호
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• pp.287-295
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• 1998

The Saccharomyces cerevisiae MGMT gene encodes a O6-methylguanine DNA methyltransferase that protects cells from mutation or death by DNA alkylating agents. Using an in vitro transcription system, we analyzed its promoter region to find regulatory elements for transcription initiation. DNase I footprinting and a transcription assay showed that a functional TATA box, 5'-TGATATAGCA-3', is located in the region spanning from -25 to -34. We also found one upstream repressing sequence (URS), -333 to -213, by promoter deletion and competition analysis. Gel mobility shift assays and Southwestern blot analysis using URS region indicate specific complex formations. These results indicate that several cis-acting and trans-acting elements might be involved in the transcriptional regulation of the S. cerevisiae MGMT gene.

• 한국통신학회논문지
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• 제35권8B호
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• pp.1159-1169
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• 2010

This paper introduces the mobility-adaptive QoE provisioning solution. The key is placed on the intelligent selection of access network depending on the QoE criteria classified by the user mobility and the bandwidth demand for service. We further focus on the network-based smart handover scheme using the mobility-adaptive handover decision and the enhanced MIH-FMIP framework. The concept is the network-based calm service and the balance in order to facilitate vertical and seamless handover. In result, it is figured out that our solution improves QoE performance by selecting appropriate access network, repressing handover occurrence, and reducing handover delay as well.

• BMB Reports
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• 제55권3호
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• pp.125-135
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• 2022

Continuously renewing the proteome, translation is exquisitely controlled by a number of dedicated factors that interact with the ribosome. The RNA helicase DDX3 belonging to the DEAD box family has emerged as one of the critical regulators of translation, the failure of which is frequently observed in a wide range of proliferative, degenerative, and infectious diseases in humans. DDX3 unwinds double-stranded RNA molecules with coupled ATP hydrolysis and thereby remodels complex RNA structures present in various protein-coding and noncoding RNAs. By interacting with specific features on messenger RNAs (mRNAs) and 18S ribosomal RNA (rRNA), DDX3 facilitates translation, while repressing it under certain conditions. We review recent findings underlying these properties of DDX3 in diverse modes of translation, such as cap-dependent and cap-independent translation initiation, usage of upstream open reading frames, and stress-induced ribonucleoprotein granule formation. We further discuss how disease-associated DDX3 variants alter the translation landscape in the cell.

• Journal of Microbiology and Biotechnology
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• 제10권3호
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• pp.287-292
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• 2000

Recombinant Aspergillus niger was constructed to express and secrete a biologically active murine granulaocyte macrophage-colony stimulating factor (mGM-CSF). A 500 bp fragment encoding the signal peptide and terminator of glyceraldehyde-3-phosphate dehydrogenase (gpd). The hygromycin phosphotrasferase gene (hph) was used as a selection marker for the fungal transformants. An expression vector was introduced into A. niger ATCC 9642, and a Northern blot analysis indicated the presence of a considerable amount of transcripts from the introduced mGM-CSF. The biological activity of recombinant mGM-CSF (rmGM-CSF) isolated from the culture filtrate was confirmend by measuring the proliferationof the GM-CSF dependent FDC-P1 cell line. It appeared that rmGM-CSF was amenable to the proteolytic activity produced by A. niger, since biological actibity was only observed when the transformants were grown in a protease-repressing medium, and the activity of rmGM-CSF dramatically decreased with an increase of age of the culture. The yield of rmGM-CSF, as determined by ELISA. was 640 ng/l of culture filtrate. Accordingly, its specific activity is estimated to be approximately two-and-a-half times higher than that of a commercial preparation from E. coli.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1996년도 자동차부품 제작기술의 진보
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• pp.35-46
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• 1996

The powder forging process offers beneficial material utilization as well as the minimization of finishing operations over that of conventionally forged rods. In the present work, the sintering behavior of Fe-2Cu-0.6C-0.35MnS, optimum preform design and forgeability of various forging conditions were investigated. This data were generated using a newly proposed sub-scaled con-rod specimen developed specifically to simulate the powder forging process. The results of present work, powder perform is so difficult to flow material into die cavity and mass flow has no effect on improving the strength. And, applied force to increase density of the specimen flowed material is greater than that of all repessing mode. On the contrary, the specimen flowed material became increased hardness of inside in contrast with all repressing mode, but the tensile strength were decreased with residual porosity in surface. Due to material flow characteristic of powder preform, the section of lower density in powder preform became also lower density in forged con-rod. So, preform design is very important in manufacturing powder forged connecting rod.

• 한국수산과학회지
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• 제37권5호
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• pp.372-379
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• 2004

This study evaluated polymanuronates on the differentiation of 3T3-L1 adipocytes. Polymannuronates increased glucose utilization and reduced the accumulation of triglycerides in the cells. The differentiation showed the same results as Oil red O staining. Also, the polymannuronates inhibited GPDH activity as a result of the restrained adipogenesis promotion process in 3T3-L1 adipocytes. The addition of the differentiation promotion factor to 3T3-L1 promoted the differentiation of adipocytes and increased the expression of the leptin level. However the addition of polymannuronates inhibited differentiation of adipocytes and the leptin secretion level in cells by checking the leptin protein level in the culture media. As well as this, it also inhibited the transcriptional mechanism and leptin mRNA expression. These results suggest that the addition of polymannuronates improves the physiological function of 3T3-L1 cells by reducing the accumulation of triglyceride and GPDH activity, and the repressing expression of leptin at a molecular level.

• 한국분말재료학회지
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• 제5권2호
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• pp.145-153
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• 1998

W-Cu alloy is attractive to thermal managing materials in microelectronic devices because of its good thermal properties. The metal injection molding (MIM) of W-Cu systems can satisfy the need for mass production of the complex shaped W-Cu parts in semiconductor devices. In this study, the application of MIM process of the mechanically alloyed (MA) W-Cu composite powders, which had higher sinterability were investigated. The MA W-Cu powders and reduction treated (RT) powders were injected by using of the multicomponent binder system. The multi-stage debinding cycles were adopted in $N_2$ and $H_2$ atmosphere. The isostatic repressing treatment was carried out in order to improve the relative density of brown parts. The brown part of RT W-Cu composite powder sintered at 110$0^{\circ}C$ had shown the higher sinterability compared to that of MA powder. The relative sintered density of all specimens increased to 96% by sintering at 120$0^{\circ}C$ for 1 hour. The relationship between green density and the sintering behavior of MA W-Cu composite powder was analyzed and discussed on the basis of the nanostructured characteristics of the MA W-Cu composite powder.

• Molecules and Cells
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• 제26권6호
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• pp.576-582
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• 2008

Nervous system development takes place after positional information has been established along the dorsal-ventral (D/V) axis. The initial subdivision provided by a gradient of nuclear dorsal protein is maintained by the zygotic genes expressed along the D/V axis. In this study, an investigation was conducted to determine the range of Dpp function in repressing the expression of eagle (eg) that is present in intermediate neuroblasts defective (ind) and muscle specific homeobox (msh) gene domain. eg is expressed in neuroblast (NB) 2-4, 3-3 and 6-4 of the msh domain, and NB7-3 of the ind domain at the embryonic stage 11. In decapentaplegic (dpp) loss-of-function mutant embryos, eg was ectopically expressed in the dorsal region, while in dpp gain-of-function mutants produced by sog or sca-GAL4/UAS-dpp, eg was repressed by Dpp. It is worthy of note that Dpp produced from sim;;dpp embryos showed that Dpp could function at long range. However, Dpp produced from en-GAL4/UAS-dpp or wg-GAL4/UAS-dpp primarily acted at short-range. This result demonstrated that this discrepancy seems to be due to the repression of Dpp to EGFR signaling in sim;;dpp embryos. Taken together, these results suggest that Dpp signaling works at short-range, but can function indirectly at long-range by way of repression of EGFR signaling during embryonic neurogenesis.

• 한국축산식품학회지
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• 제37권3호
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• pp.368-375
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• 2017

Clostridium difficile infection (CDI) is the main cause of hospital-acquired diarrhea that can cause colitis or even death. The medical-treatment cost and deaths caused by CDI are increasing annually worldwide. New approaches for prevention and treatment of these infections are needed, such as the use of probiotics. Probiotics, including Bifidobacterium spp. and Lactobacillus, are microorganisms that confer a health benefit to the host when administered in adequate amounts. The effect of Bifidobacterium longum ATCC 15707 on infectious disease caused by C. difficile 027 was investigated in a mouse model. The survival rates for mice given the pathogen alone, and with live cells, or dead cells of B. longum were 40, 70, and 60%, respectively. In addition, the intestinal tissues of the B. longum-treated group maintained structural integrity with some degree of damage. These findings suggested that B. longum ATCC 15707 has a function in repressing the infectious disease caused by C. difficile 027.