• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.869-873
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• 2010

A series of novel chiral tert-amino alcohols 4a-h derived from enantiomerically pure phenylalanine were synthesized efficiently and used as chiral ligands in the catalytic enantioselective ethylation of aldehydes with diethylzinc (diethylzinc-to-aldehyde addition). The use of 10 mol % of the amino alcohols led to the corresponding sec-alcohols with excellent enantioselectivities (up to 100% ee) and high yields.

• 천문학논총
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• 제30권2호
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• pp.289-292
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• 2015

Most of the stars in the Galaxy are in binary systems. Binaries should be possible as the hosting stars of planets. Searching for planetary companions to binaries, especially evolved close binary stars, can provide insight into the formation and the ultimate fate of circumbinary planets and shed light on the late evolution of binary stars. In order to do this, we have chosen some post common envelope binaries including sdB-type eclipsing binaries and detached WD+dM eclipsing binaries as our targets and monitored them for several years. In this paper, we will present some of our new observations and results for three targets, NSVS 07826147, NSVS14256825 and RR Cae.

• Journal of Information Processing Systems
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• 제19권3호
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• pp.302-309
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• 2023

Artificial intelligence (AI) plays a crucial role in the intelligent development of China's power system. It is also an important part of the digital development of the power grid. The development of AI determines whether the digital transformation of China's power system can be successfully implemented. Therefore, this paper discusses the digital transformation of the power grid based on AI technologies. The author has established a digital evaluation index system to reflect the development of the power grid in one province. Both qualitative and quantitative methods have been adopted in the analysis, which delves into the economic effectiveness, quality, and coordination of power grid development in the province in a comprehensive way. Results show that, to meet the needs of the power grid's digital transformation, the correlation coefficient between the power grid's development and the province's overall coordination has been increasing in recent years.

• Bulletin of the Korean Chemical Society
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• 제25권4호
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• pp.549-552
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• 2004

A sensitive, selective and rapid method has been developed for the determination of mercury based on the rapid reaction of mercury(II) with p-sulfobenzylidenethiorhodanine (SBDTR) and the solid phase extraction of the colored chelate with $C_{18}$ disks. In the presence of pH 3.5 sodium acetate-acetic acid buffer solution and Emulsifier-OP medium, SBDTR reacts with mercury(II) to form a red chelate of a molar ratio 1 : 2 (mercury to SBDTR). This chelate was prconcentrated by solid phase extraction with $C_{18}$ disks. An enrichment factor of 50 was achieved. The molar absorptivity of the chelate is $1.28{\times}10^5 L{\cdot}mol^{-1}{\cdot}cm^{-1}$ at 545 nm in measured solution. Beer's law is obeyed in the range of 0.01-3 ${\mu}$g/mL. The relative standard deviation for eleven replicates sample of 0.01 ${\mu}$g/mL is 1.65%. This method was applied to the determination of mercury in tobacco and tobacco additive with good results.

• Bulletin of the Korean Chemical Society
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• 제31권7호
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• pp.1968-1972
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• 2010

Pt-Co alloy nanowire array was directly synthesized by electrochemical deposition with polycarbonate template at -1.0V and subsequent chemical etching of the template. The use of Pt-Co alloy nanowire array-modified electrode (Pt-Co NAE) for the determination of morphine (MO) is described. The morphology of the Pt-Co alloy nanowire array has been investigated by scanning electron microscopy (SEM) and energy disperse X-ray spectroscopy (EDS) analysis), respectively. The resulting Pt-Co NAE offered a linear amperometric response for morphine ranging from $2.35\times10^{-5}$ to $2.39\times10^{-3}$ M with a detection limit of $7.83\times10^{-6}$ M at optimum conditions. This sensor displayed high sensitivity and long-term stability.

• Bulletin of the Korean Chemical Society
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• 제30권2호
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• pp.454-458
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• 2009

Polypyrrole (PPy) nanotubes have been synthesized by chemical oxidative polymerization of pyrrole within the pores of polycarbonate membrane using the technology of diffusion of solutes. The nanotubes array prepared by the proposed method can be considered as nanoelectrode ensembles (NEEs). An amperometric uric acid sensor based on PPy NEEs has been developed and used for determination of uric acid in human serum samples. The electrode can direct response to uric acid at potential of 0.60V vs. SCE with wide linear range of $1.52{\times}10^{-6}\;to\;1.54{\times}10^{-3}\;M.\;The\;detection\;limit\;is \;3.02{\times}10^{-7}$ M. This sensor has been used to determine uric acid in real serum samples. PPy NEEs is thought of as a good application in the foreground.

• Bulletin of the Korean Chemical Society
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• 제34권1호
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• pp.63-67
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• 2013

A bottom-modified (4-position) naphthalimide derivative 1 with 1,8-naphthyridine as binding site has been designed and synthesized. Compound 1 is the first 1,8-naphthyridine-modified naphthalimide-based sensor that can detect $Hg^{2+}$ selectively with respect to ratiometric fluorescent change and blue shift in organic aqueous solution. The Job's plot and FAB mass indicate that 1 formed a 1:1 complex with $Hg^{2+}$. A top-modified naphthalimide derivative 2 with 1,8-naphthyridin as binding site has also been synthesized for comparison.

• Journal of Microbiology and Biotechnology
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• 제29권8호
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• pp.1255-1265
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• 2019

To investigate the diversity of gastrointestinal microflora and lignocellulose-degrading enzymes in wild Asian elephants, three of these animals living in the same group were selected for study from the Wild Elephant Valley in the Xishuangbanna Nature Reserve of Yunnan Province, China. Fresh fecal samples from the three wild Asian elephants were analyzed by metagenomic sequencing to study the diversity of their gastrointestinal microbes and cellulolytic enzymes. There were a high abundance of Firmicutes and a higher abundance of hemicellulose-degrading hydrolases than cellulose-degrading hydrolases in the wild Asian elephants. Furthermore, there were a high abundance and a rich diversity of carbohydrate active enzymes (CAZymes) obtained from the gene set annotation of the three samples, with the majority of them showing low identity with the CAZy database entry. About half of the CAZymes had no species source at the phylum or genus level. These indicated that the wild Asian elephants might possess greater ability to digest hemicellulose than cellulose to provide energy, and moreover, the gastrointestinal tracts of these pachyderms might be a potential source of novel efficient lignocellulose-degrading enzymes. Therefore, the exploitation and utilization of these enzyme resources could help us to alleviate the current energy crisis and ensure food security.

• 한국축산식품학회지
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• 제43권6호
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• pp.975-988
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• 2023

The fatty acid composition and small molecular metabolites in breast and leg meat of Yanjin blackbone chickens (YBC) and Piao chickens (PC) were detected by gas chromatography-mass spectrometry and liquid chromatography-quadrupole static field orbital trap mass spectrometry. Thirty-two fatty acids were detected, and the total fatty acid content of PC was significantly higher than that of YBC (p<0.05). Oleic acid, linoleic acid, palmitic acid, stearic acid, and arachidonic acid were the main fatty acids in the two chicken varieties, and the composition of fatty acids in the two varieties were mainly unsaturated fatty acids, being more than 61.10% of the total fatty acids. Meanwhile, 12 and 16 compounds were screened out from chicken legs and chicken breasts of YBC and PC, respectively, which had important contributions to the differences between groups.

• Asian Pacific Journal of Cancer Prevention
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• 제13권11호
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• pp.5653-5657
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• 2012

Objectives: To investigate the effect of glycopeptide-preferring polypeptide GalNAc transferase 1 (ppGalNAc T1 ) targeted RNA interference (RNAi) on the growth and migration of human bladder carcinoma EJ cells in vitro and in vivo. Methods: DNA microarray assays were performed to determine ppGalNAc Ts(ppGalNAc T1-9) expression in human bladder cancer and normal bladder tissues. We transfected the EJ bladder cancer cell line with well-designed ppGalNAc T1 siRNA. Boyden chamber and Wound healing assays were used to investigate changes of shppGalNAc T1-EJ cell migration. Proliferation of shppGalNAc T1-EJ cells in vitro was assessed using [3H]-thymidine incorporation assay and soft agar colony formation assays. Subcutaneous bladder tumors in BALB/c nude mice were induced by inoculation of shppGalNAc T1-EJ cells and after inoculation diameters of tumors were measured every 5 days to determine gross tumor volumes. Results: ppGalNAc T1 mRNA in bladder cancer tissues was 11.2-fold higher than in normal bladder tissues. When ppGalNAc T1 expression in EJ cells was knocked down through transfection by pSUPER-shppGalNAc T1 vector, markedly reduced incorporation of [3H]-thymidine into DNA of EJ cells was observed at all time points compared with the empty vector transfected control cells. However, ppGalNAc T1 knockdown did not significantly inhibited cell migration (only 12.3%). Silenced ppGalNAc T1 expression significantly inhibited subcutaneous tumor growth compared with the control groups injected with empty vector transfected control cells. At the end of observation course (40 days), the inhibitory rate of cancerous growth for ppGalNAc T1 knockdown was 52.5%. Conclusion: ppGalNAc T1 might be a potential novel marker for human bladder cancer. Although ppGalNAc T1 knockdown caused no remarkable change in cell migration, silenced expression significantly inhibited proliferation and tumor growth of the bladder cancer EJ cell line.