• Bulletin of the Korean Chemical Society
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• v.30 no.8
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• pp.1767-1770
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• 2009

The Henry (nitroaldol) reaction proceeds under mild conditions with catalytic amount of tetramethylethylenediamine (TMEDA) to afford $\beta$-nitro alkanol in considerably excellent yield. Structurally diverse aldehydes react with nitromethane in presence of 0.3 equiv of TMEDA under solvent-free condition at rt. The low catalytic loading and mild reaction condition are the key features of the catalytic method.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.09a
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• pp.147-163
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• 2003

European Union bans the usage of Pb in electronics from July 1 st, 2006. The Near-eutectic Sn-Ag-Cu alloys are the leading candidate Pb-free solders (for SMT card assembly). .The microstructure of Sn-Ag-Cu alloys is discussed in terms of solidification, composition and cooling rate. Methods of controlling Ag3Sn plates are discussed. .Thermo-mechanical fatigue behaviors of Sn-Ag-Cu solder joints are reviewed. Tin pest, whisker growth, electromigration of Pb-free solders are discussed.

• Biomedical Science Letters
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• v.17 no.3
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• pp.173-176
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• 2011

Free-living Acanthamoeba are eukaryotic protozoan organisms that are widely distributed in the air, water, etc such as environment. Acanthamoeba ingest the Escherichia coli which will replicate in cytoplasm of Acanthamoeba. Bacterial pathogenicity or virulence is one of important determinant factors to survive in free-living Acanthamoeba and otherwise Acanthamoebic pathogenicity is also an important factor for their interactions. Bacterial association with pathogenic strain of Acanthamoeba T1 and T4 was lower about two times than non-pathogenic T7. Bacterial invasion percentages into T1 were higher about three times than T7 but bacterial survival in T7 was increased as T1. The capsule-deletion mutant exhibited limited ability for invasion/uptake by and survival inside pathogenic Acanthamoeba T4. E. coli-outer membrane protein A (OmpA) decreased bacterial association with A. castellanii by about three times and it had higher effects than lipopolysaccharides (LPS). Under favorable conditions, the mutants were not survived in Acanthamoeba up to 24 h incubation. Therefore, this review will report pathogenic and non-pathogenic Acanthamoeba strains interactions with E. coli and its several mutants, i.e., capsule, OmpA and LPS.

• Korean Journal of Plant Resources
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• v.37 no.3
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• pp.247-255
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• 2024

In this study, we aimed to verify the anti-obesity activity of R. acicularis leaves (RAL) and elucidate its mechanism of action in 3T3-L1 preadipocytes. RAL dose-dependently inhibited the accumulation of lipid droplets and triacylglycerol. RAL did not affect cell proliferation and survival in undifferentiated 3T3-L1 cells, but it inhibited cell proliferation in differentiating 3T3-L1 cells. RAL increased ATGL, p-HSL, and HSL, and decreased perilipin-1 in differentiating 3T3-L1 cells. In addition, RAL reduced lipid droplet accumulation and increased free glycerol content in differentiated 3T3-L1 cells. RAL increased ATGL and HSL in differentiated 3T3-L1 cells. Also, RAL increased p-AMPK, PPARγ, UCP-1, and PGC-1α in differentiating 3T3-L1 cells. AMPK inhibition by compound C attenuated RAL-mediated increase of ATGL, HSL, PPARγ, and UCP-1 in 3T3-L1 cells. Taken together, it is thought that RAL may inhibit lipid accumulation through lipolysis and thermogenesis via the activation of AMPK in adipocytes.

• The Korean Journal of Urological Oncology
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• v.16 no.3
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• pp.119-125
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• 2018

Purpose: We compared subtypes of papillary renal cell carcinoma (pRCC; types 1 and 2) and clear cell renal cell carcinoma (ccRCC) in patients with T1-stage RCC to analyze the impact of the subtype on oncological outcomes. Materials and Methods: This paper reviewed 75 patients with pRCC and 252 patients with ccRCC at T1-stage from 1998-2012. Thus, we assessed the impact of subtype on oncologic outcomes among patients with T1-stage RCC. We used Kaplan-Meier analysis to estimate the overall survival and recurrence-free survival The median follow-up duration was 95 months (interquartile range, 75.4-119.3 months). Results: The 5-year recurrence-free survivals of pRCC and ccRCC were 95.4% and 97.6%, respectively. pRCC is worse than ccRCC in terms of recurrence-free survival (p=0.008) and there was no significant difference in the overall survival between pRCC and ccRCC (p=0.32). In addition, there was no significant statistical difference between type 1 pRCC and type 2 pRCC in terms of either recurrence-free survival (p=0.526) or overall survival (p=0.701). Age (hazard ratio [HR], 1.069; p<0.001) and recurrence (HR, 4.93; p<0.001) were predictors of overall survival. Only tumor size (HR, 1.071; p=0.004) was predictors in the case of cancer specific survival in the multivariate analysis. Conclusions: Among patients with T1-stage RCC, recurrence after surgery was more common in pRCC than ccRCC. The subtype of pRCC (types 1 and 2) had no impact on the recurrence-free survival or overall survival.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.1
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• pp.22-30
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• 2004

As an information-oriented society comes, many people use PC and depend on database that network server has. However, the online data can be missed when a blackout happens and also a power failure effects on standard of judgment on Power Quality. Thus, it is reason of a trend using interruption-free live-line work when a trouble happens to power system. However, the 83％ among the number of people who receive an electric shock experience when a laborer is doing interruption-free live-line works. In interruption-free method, the education and the training problem has been issued. However, we have a few instructors for that training. Furthermore, the trainees have short training period, just 4 weeks. In this paper, to develope the method that has no restriction of a time and place and reduce the wasteful materials, immersion type virtual reality(or environment) technology is used. The users of a 3D immersion type VR training system can interact with the system by doing same action in the real safe environment. Thus, it can be valuable to apply this training system to a dangerous work like as "Interruption-free live-line work exchanging COS(Cut-Out-Switch)". In this program, the user works with a instruction on the window and speaker and can't work other tasks until each part of the task completed. The workers using this system can use their hands and viewpoint movement as he is in a real environment but the trainee can't use all parts and senses of a real body with the current VR technology. Despite of this weak point, when we consider the trends of improvement in electrical devices and communication technology, we can say that 3D graphic VR application has a high potentiality.

• Journal of Microbiology and Biotechnology
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• v.13 no.3
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• pp.344-347
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• 2003

Unnatural amino acid S-(2-nitrobenzyl)cysteine was incorporated into human erythropoietin by using a programmed suppression of nonsense codon in a cell-free protein synthesis system. Several controlling factors affecting the operational efficiency of the suppression were investigated and optimized. The amount of suppressor tRNA and the concentration of $Mg^2+$ were crucial not only for the efficiency but also for the control of the exact suppression. In addition, some general optimization factor are reported in order to improve the efficiency in an unnatural amino acid mutagenesis.

• Journal of the Korean Mathematical Society
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• v.49 no.2
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• pp.405-417
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• 2012

We find the Hilbert function and the minimal free resolution of a star-configuration in $\mathbb{P}^n$. The conditions are provided under which the Hilbert function of a star-configuration in $\mathbb{P}^2$ is generic or non-generic We also prove that if $\mathbb{X}$ and $\mathbb{Y}$ are linear star-configurations in $\mathbb{P}^2$ of types t and s, respectively, with $s{\geq}t{\geq}3$, then the Artinian k-algebra $R/(I_{\mathbb{X}}+I_{\mathbb{Y})$ has the weak Lefschetz property.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.1
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• pp.47-54
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• 2000

Transition metal ions including $Se^{2+},\;Cd^{2+},\;Hg^{2+}\;or\;Mn^{2+}$ have been thought to disturb the bone metabolism directly. However, the mechanism for the bone lesion is unknown. In this study, we demonstrated that MC3T3E1 osteoblasts, exposed to various transition metal ions; selenium, cadmium, mercury or manganese, generated massive amounts of reactive oxygen species (ROS). The released ROS were completely quenched by free radical scavengers-N-acetyl cysteine (NAC), reduced glutathione (GSH), or superoxide dismutase (SOD). First, we have observed that selenium $(10\;{\mu}M),$ cadmium $(100\;{\mu}M),$ mercury $(100\;{\mu}M)$ or manganese (1 mM) treatment induced apoptotic phenomena like DNA fragmentation, chromatin condensation and caspase-3-like cysteine protease activation in MC3T3E1 osteoblasts. Concomitant treatment of antioxidant; N-acetyl-L-cysteine (NAC), reduced-form glutathione (GSH), or superoxide dismutase (SOD), prevented apoptosis induced by each of the transition metal ions. Catalase or dimethylsulfoxide (DMSO) has less potent inhibitory effect on the apoptosis, compared with NAC, GSH or SOD. In line with the results, nitroblue tetrazolium (NBT) stain shows that each of the transition metals is a potent source of free radicals in MC3T3E1 osteoblast. Our data show that oxidative damage is associated with the induction of apoptosis in MC3T3E1 osteoblasts following $Se^{2+},\;Cd^{2+},\;Hg^{2+}\;or\;Mn^{2+}$ treatment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1137-1144
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• 2015

This study examined the impact of osteoporosis on thyroid hormone in health check-up examinees. The study subjects were 1,117 adults, 20 years and over (636 males, 481 females), who underwent a health package check-up at the general hospital G from January to December, 2011. After adjusting for factors, such as year and gender, the mean thyroid stimulating hormone increased with decreasing T-score (Normal[${\geq}-1g/cm^2$], $1.61{\pm}0.07{\mu}IU/m{\ell}$ and osteopenia[-1 >, ${\geq}-2.5g/cm^2$],$1.82{\pm}0.08{\mu}IU/m{\ell}$ and osteoporosis[< $-2.5g/cm^2$],$3.14{\pm}0.27{\mu}IU/m{\ell}$). After adjusting for factors, such as gender and FBS, the mean free thyroxine decreased with decreasing T-score(Normal, $1.30{\pm}0.01ng/d{\ell}$, and osteopenia, $1.22{\pm}0.01ng/d{\ell}$, and osteoporosis, $1.13{\pm}0.04ng/d{\ell}$). Conclusion. These results suggest that a decrease in T-score might increase the thyroid stimulating hormone and decrease the free thyroxine levelin euthyroid adults.