• Archives of Pharmacal Research
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• v.25 no.5
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• pp.600-607
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• 2002

Two series of 2,3-diarylcyclopent-2-ene-1-ones including 2-aryl-3-(2,5-dihydroxyphenyl)cyclopent-2-ene-1-ones (2a∼2f) and 3-aryl-2-(3',4',5'-trimethoxyphenyl)cyclopent-2-ene-1-one (3a∼3j) were synthesized and evaluated for the cytotoxicity against three tumor cell lines; B16F10, HCT116 and A431. It was found that the 3,4,5-trimethoxy substituent was optimal for the bioactivity of compounds in series 2. Meanwhile, compounds in series 3 exhibited the most potent cytotoxicity with 3-aryl ring being 4-methoxyphenyl (compound 3f), (3-hydroxy-4-methoxy)phenyl (compound 3e), or (3-amino-4-methoxy)phenyl (compound 3j).

• The Journal of the Acoustical Society of Korea
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• v.18 no.4E
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• pp.3-9
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• 1999

Deep-water sonar transducers of FFR (Free Flooded Ring) type have been designed using a coupled FE-BEM. The proposed sonar transducers are composed of piezoelectric ceramic tubes and structural steel materials for simple fabrication. In order to have an omnidirectional beam pattern around 30kHz, a conic steel is placed below a piezoelectric tube or a steel disc is placed between two piezoelectric tubes. The dynamics of the sonar transducer is modelled in three dimensions and is analyzed with external electrical excitation conditions. Various results are available such as directivity patterns and transmitting voltage responses. The most optimal structure and dimensions of the steel material were calculated, so that the beam patterns of the sonar transducers had +/- 3dB omnidirectivity at 30kHz.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.591-592
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• 2006

Schottky diodes for Radio-frequency identification (RFID) tag integration on chip were designed and fabricated using Samsung electronics System LSI standard $0.18{\mu}m$ CMOS process. Schottky diodes were designed as interdigitated fingers array by CMOS layout design rule. 64 types of Schottky diode were designed and fabricated with the variation of finger width, length and numbers with a $0.6{\mu}m$ guard ring enclosing n-well. Titanium was used as Schottky contact metal to lower the Schottky barrier height. Barrier height of the fabricated Schottky diode was 0.57eV. DC current - voltage measurements showed that the fabricated Schottky diode had a good rectifying properties with a breakdown voltage of -9.15 V and a threshold voltage of 0.25 V.

• Bulletin of the Korean Chemical Society
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• v.27 no.12
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• pp.1981-1984
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• 2006

Novel amphiphilic, thermo-responsive polyaspartamides which showed both LCST (lower critical solution temperature), and sol-gel transition were prepared and characterized. The polyaspartamide derivatives were synthesized from polysuccinimide, the polycondensate of aspartic acid monomer, via successive nucleophilic ring-opening reaction by using dodecylamine and N-isopropylethylenediamine (NIPEDA). At the intermediate composition ranges, the dilute aqueous solution exhibited a thermally responsive phase separation due to the presence of LCST. The phase transition temperature was controllable by changing the content of pendent groups. In addition, a physical gelation, i.e. the sol-gel transition was observed from the concentrated solutions, which was elucidated by dynamic viscoelastic measurements. These novel injectable and thermo-responsive hydrogels have potential for various biomedical applications such as tissue engineering and current drug delivery system.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.67-70
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• 2009

Printed electronics are emerging technology to realize various microelectronic devices via a cost-effective method. Here we introduce high performance inkjet printed polymer field-effect transistors and application to complementary integrated circuits with p-type and n-type conjugated polymers. The performance of devices highly depends on the selection of dielectrics, printing condition and device architecture. The device optimization and performances of various integrated circuits, e.g., complementary inverters and ring oscillators will be mainly discussed in this talk.

• YAKHAK HOEJI
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• v.49 no.1
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• pp.103-108
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• 2005

Tacrine analogues for degenerative brain disease treatments have been designed. A series of diazaanthrine derivatives as novel analogues of tacrine has been prepared through the alkyl substitution and the ring expansion. They were expected to retain anti-inflammatory activity by inhibition of prostaglandin production with reduction of side effect as the selective prostaglandin synthase inhibitor. Prostaglandin synthase expression is associated with the deposition of beta-amyloid protein in neuritic plaques in brain inflammation. Therefore selective prostaglandin synthase blockade is important for the prevention and treatment of alzheimer's disease. To evaluate inhibitory effect of prostaglandin synthase, synthetic tacrine derivatives were screened with accumulation of prostaglandin biosynthesis by lipopolysaccharide in aspirin-treated murine macrophage cell. Most of synthetic compounds have shown significant prostaglandin synthase activities in vitro screening with $84.3{\sim}33.6\%$ inhibition of the prostaglandin $E_2$ production at $10\;{\mu}g/ml$.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.18-20
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• 1995

This paper describes a 7.5T magnetic flux density superconducting wiggler that minimize net angular deflection and displacement of an electron rotating along the orbit at storage ring in Pohang Light Source. It consist of dipole superconducting magnet,high uniformity flux distribution due to current source supply,cryostat,vacuum chamber,measurement system. In this paper magnet design procedure, manufacturing, experimental results are contained.

• Textile Coloration and Finishing
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• v.7 no.4
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• pp.39-44
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• 1995

A study has been made about some correlations in the chemical cyclization of precursors, poly(ether-amide-amic acid)s by treating in solution a mixture of acetic anhydride and pyridine in the presence of 4,4-dimethyl formamide, with the poly(ether-amic acid)s being respectively reacted between trimellitic anhydride chloride and 3 kinds of diamines, i.e., 4,4'-bis(m-aminophenoxy) benzophenone, 2,2'-bis[4-(m-aminophenoxy) phenyl] propane and 4,4'-bis(m-aminophenoxy) diphenyl sulfone. The cyclization of imide ring in the poly(ether-amide-amic acid)s may be regarded as an intramolecular acylation of amide group by o-carboxyl group. As a result of this reseach, the effects on the conversion to poly(ether-amide-imide)s have been found by changing the ratio of cosolvents in the cyclization mixture.

• Bulletin of the Korean Chemical Society
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• v.11 no.1
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• pp.31-33
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• 1990

We synthesized the novel complexes of (1,1-dimethyl-3,4-diphenyl-1-silacyclopenta-2,4-di ene-2,5-yldibenzene)bis(tricarbonylchromium) and tricarbonyl (R,R'-3,4,5-triphenyl-1-silacyclopenta-2,4-diene-2 -ylbenzene)chromium(R,R' = Me, R = Me/R' = Cl, R = Ph/R' = Cl) from the reaction of the corresponding R,R'-2,3,4,5-Tetraphenyl-1-silacyclopenta-2,4-dien e (abr. R,R'-TPSCp) with chromiumhexacarbonyl. These results reveal that chromium prefer to coordinate to the phenyl substituents of 1-silacyclospentadiene rather than the butadiene moiety of the ring.

• Bulletin of the Korean Chemical Society
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• v.21 no.9
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• pp.919-922
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• 2000

The cyclization reaction of N-(2-hydroxyethyl)-N'-phenylthioureas 2 containingambident nucleophile was ex-amined in the combination of a variety ofbases and p-toluenesulfonyl chloride (TsCl).N-(2-Hydroxyeth-yl) thioureas 2 were readily obtained in high yields from the reaction of the corresponding 1,2-aminoalcohols with phenyl isothiocyanate, avoiding the need for O-protection.The use of a one-pot reaction (NaOH/TsCl) was found to be most effective in producing the requisite 2-phenylaminothiazolines (S-cyclization) 3 in the case ofthioureas 2a-2e derived from N-unsubstituted aminoalcohols,while in the thioureas 2f and 2g prepared from N-substituted aminoalcohols the combination of Et3N and TsCl led to the S-cyclization products.