• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.108-109
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• 2014

본 논문에서는 gate와 drain bias stress하에서의 a-IGZO thin-film transistors (TFTs)의 비대칭 열화 메커니즘 분석을 진행하였다. Gate와 drain bias stress하에서의 a-IGZO TFT의 열화 현상은 conduction band edge 근처에 존재하는 oxygen vacancy-related donor-like trap의 발생으로 예상되며, TFT의 channel layer 내에서의 비대칭 열화현상은 source의 metal과 a-IGZO layer간의 contact에 전압이 인가되었을 경우, reverse-biased Schottky diode에 의한 source 쪽에서의 높은 electric field가 trap generation을 가속화시킴으로써 일어나는 것임을 확인할 수 있었다.

• Journal of Electrical Engineering and Technology
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• v.13 no.5
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• pp.2067-2073
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• 2018

This paper will present the design of a novel-type velocity-controllable electromagnetic coil launcher (EMCL). By studying the influence of initial capacitor voltage on the velocity of an EMCL, the launcher voltage can be set to precisely adjust the velocity of projectile launching. The simulation of voltage and velocity in relation to time is obtained by Maxwell software. The experimental data show that for the launch accuracy to be achievable, the actual precision is 2%. Because of the excellent performance of Velocity-controllable EMCL, it can replace the air gun and applied to split Hopkinson pressure bar (SHPB).

• Coupled systems mechanics
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• v.2 no.3
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• pp.215-230
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• 2013

This paper investigates the pull-in instability of functionally graded poly-SiGe micro-beams under the combined electrostatic and intermolecular forces and temperature change. The exponential distribution model and Voigt model are used to analyze the functionally graded materials (FGMs). Principle of virtual work is used to derive the nonlinear governing differential equation which is then solved using differential quadrature method (DQM). A parametric study is conducted to show the significant effects of material composition, geometric nonlinearity, temperature change and intermolecular Casimir force.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.8
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• pp.1072-1079
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• 2013

The NLRP12 (NLR family, pyrin domain containing 12) serves as a suppressor factor in the inflammatory response and protects the host against inflammation-induced damage. In the present study, we aimed to study the polymorphisms of NLRP12 gene and its association with susceptibility to non-specific digestive disorder (NSDD) in rabbits. We re-sequenced the entire coding region of the rabbit NLRP12 gene and detected a total of 19 SNPs containing 14 synonymous and five non-synonymous variations. Among them, the coding SNP (c.1682A>G), which would carry a potential functional implication, was subsequently subjected to genotyping for case-control association study (272 cases and 267 controls). The results revealed that allele A was significantly protective against NSDD with an odds ratio value of 0.884 (95% confidence interval, 0.788 to 0.993; p = 0.038). We also experimentally induced NSDD in growing rabbits by feeding a fibre-deficient diet and subsequently investigated NLRP12 mRNA expression. The mRNA expression of NLRP12 in healthy status was significantly higher than that in severe NSDD (p = 0.0016). The highest expression was observed in individuals carrying the protective genotype AA (p = 0.0108). These results suggested that NLRP12 was significantly associated with the NSDD in rabbits. However, the precise molecular mechanism of NLRP12 involving in the development of rabbit NSDD requires further research.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.4103-4107
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• 2015

Background: Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies worldwide. Transarterial chemoembolisation (TACE) is the standardized therapy for intermediate stage HCC. However, the prognosis for HCC patients treated by TACE greatly varies. Thus, there is a critical need for finding biomarkers to predict the prognosis of HCC patients. The amino acid transporter-2 (ASCT2) is involved in tumorigenesis and progression of many malignancies. This study aimed to evaluate the predictive role of two single nuclear polymorphisms (SNPs, rs3826793 and rs2070246) in the ASCT2 gene in HCC patients treated by TACE. Materials and Methods: Two functional SNPs (rs3826793 and rs2070246) in the ASCT2 gene were selected and genotyped using the Sequenom iPLEX genotyping system in a cohort of 448 unresectable Chinese HCC patients treated by TACE. Univariate and multivariate Cox proportional hazards models and Kaplan-Meier curves were used for the prognosis analyses. Results: There was no significant association between two SNPs (rs3826793 and rs2070246) in the ASCT2 gene and overall survival of TACE treated HCC patients. However, we demonstrated that patients with early stage HCC carrying T genotype in rs2070246 showed better OS than those carrying CC genotype (P=0.023). Conclusions: We demonstrated that patients with early stage HCC carrying T genotype in rs2070246 showed better OS than those carrying CC genotype.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3363-3368
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• 2014

Background: Curcumin, a phenolic compound extracted from the rhizomes of Curcuma longa, has shown cytotoxic effects against a variety of cancers. The aim of this study was to identify potential microRNA (miRNA) mediators of the anticancer effects of curcumin in ovarian cancer cells. Materials and Methods: SKOV3 ovarian cancer cells were treated with curcumin ($10-60{\mu}M$) and miR-9 expression, cell proliferation, and apoptosis were assessed. The effects of miR-9 depletion on curcumin-mediated growth suppression were also examined. Phosphorylation of Akt and forkhead box protein O1 (FOXO1) was measured in cells with miR-9 overexpression or curcumin treatment. Results: Curcumin caused a significant and dose-dependent increase of miR-9 expression in SKOV3 cells, while significantly impeding cell proliferation and stimulating apoptosis. Depletion of miR-9 significantly (p<0.05) attenuated the growth-suppressive effects of curcumin on SKOV3 cells, coupled with reduced percentages of apoptotic cells. In contrast, overexpression of miR-9 significantly enhanced the cleavage of caspase-3 and poly(ADP-ribose) polymerase and promoted apoptotic death in SKOV3 cells. Western blot analysis showed that both miR-9 overexpression and curcumin similarly caused a significant (p<0.05) decline in the phosphorylation of Akt and FOXO1, compared to untreated cells. Conclusions: The present study provided evidence that curcumin exerts its cytotoxic effects against SKOV3 ovarian cancer cells largely through upregulation of miR-9 and subsequent modulation of Akt/FOXO1 axis. Further studies are needed to identify direct targets of miR-9 that mediate the anticancer effects of curcumin in ovarian cancer cells.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4765-4768
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• 2013

Aims: This study was conducted to evaluate the levels of TNF-${\alpha}$, IL-6, IL-8 and VEGF in serum of patients with non- small cell lung cancer, for assessing their possible diagnostic and prognostic roles. Methods: We enrolled 48 patients newly diagnosed with non-small cell lung cancer and 40 healthy controls. TNF- ${\alpha}$, IL-6 and IL-8 levels were measured in the serum of all the subjects with specific radioimmunoassay kits, while EGF was analyzed by sandwich enzyme immunoassay techniques. Results: A statistically significant difference was observed between lung cancer patients and the control group regarding the values of TNF-${\alpha}$, IL-6, IL-8 and VEGF in serum. Moreover, TNF-${\alpha}$, IL-8 and VEGF levels were higher in patients with advanced stages compared to early stages. In addition, higher serum levels of TNF-${\alpha}$, IL-6, IL-8 and VEGF were found in smokers than in non-smokers, both in patients and controls. Conclusion: Serum levels of TNF-${\alpha}$, IL-6, IL-8 and VEGF were all elevated in lung cancer patients, suggesting that inflammatory cytokines could be jointly used as a screening tool. Though TNF-${\alpha}$, IL-8 and VEGF levels were related to advanced disease, long-term survival studies of NSCLC patients should be performed to confirm whether they can act as biomarkers of advanced disease. In addition, smoking would be an important contributor to the processes of inflammation and lung cancer.

• Journal of Microbiology and Biotechnology
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• v.28 no.7
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• pp.1147-1155
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• 2018

The degradation efficiency and catabolism pathways of the different methylxanthines (MXs) in isolated caffeine-tolerant strain Pseudomonas putida CT25 were comprehensively studied. The results showed that the degradation efficiency of various MXs varied with the number and position of the methyl groups on the molecule (i.e., xanthine > 7-methylxanthine ${\approx}$ theobromine > caffeine > theophylline > 1-methylxanthine). Multiple MX catabolism pathways coexisted in strain CT25, and a different pathway would be triggered by various MXs. Demethylation dominated in the degradation of N-7-methylated MXs (such as 7-methylxanthine, theobromine, and caffeine), where C-8 oxidation was the major pathway in the catabolism of 1-methylxanthine, whereas demethylation and C-8 oxidation are likely both involved in the degradation of theophylline. Enzymes responsible for MX degradation were located inside the cell. Both cell culture and cell-free enzyme assays revealed that N-1 demethylation might be a rate-limiting step for the catabolism of the MXs. Surprisingly, accumulation of uric acid was observed in a cell-free reaction system, which might be attributed to the lack of activity of uricase, a cytochrome c-coupled membrane integral enzyme.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3359-3365
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• 2010

The incorporation of microwave irradiation with the prevalent "click chemistry" is currently of considerable synthetic interest. We describe here the introduction of such laboratorial shortcut into carbohydrate-based drug discovery, resulting in the rapid formation of a series of triazole-linked salicylic $\beta$-D-O-glycosides with biological activities. All "clicked" products were achieved in excellent yields ($\approx$ 90%) within only a quarter. In addition, based on the structural characteristics of the afforded glycomimetics, their inhibitory activities were evaluated toward protein tyrosine phosphatases 1B (PTP1B) and a panel of homologous protein tyrosine phosphatases (PTPs). Docking simulation was also conducted to plausibly propose binding modes of this glycosyl salicylate series with the enzymatic target.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.4157-4162
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• 2012

Background: Novel prognostic biomarkers or therapeutic molecular targets for laryngeal squamous cell carcinoma (LSCC) are an urgent priority. We here sought to identify multiple novel LSCC-associated genes. Methods: Using high-density microarray expression profiling, we identified multiple genes that were significantly altered between human LSCCs and paired normal tissues. Potential oncogenic functions of one such gene, DCUN1D5, were further characterized in vitro. Results: Our results demonstrated that DCUN1D5 was highly expressed in LSCCs. Overexpression of DCUN1D5 in vitro resulted in 2.7-fold increased cellular migration, 67.5% increased invasive capacity, and 2.6-fold increased proliferation. Endogenous DCUN1D5 expression was decreased in a time-dependent manner after genotoxic stress, and silencing of DCUN1D5 by siRNA decreased the number of cells in the S phase by 10.2% and increased apoptosis by 11.7%. Conclusion: Our data suggest that DCUN1D5 in vitro might have vital roles in DNA damage response, but further studies are warranted to assess its significance in vivo.