• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.541-548
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• 2012

New candidates composed of anthracene and 4-alkylethynylbenzene end-capped oligomers for OTFTs were synthesized under Sonogashira coupling reaction conditions. All oligomers were characterized by FT-IR, mass, UV-visible, and PL emission spectrum analyses, cyclic voltammetry (CV), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), $^1H$-NMR, and $^{13}C$-NMR. Investigation of their physical properties showed that the oligomers had high oxidation potential and thermal stability. Thin films of DHPEAnt and DDPEAnt were characterized by spin coating them onto Si/$SiO_2$ to fabricate top-contact OTFTs. The devices prepared using DHPEAnt and DDPEAnt showed hole field-effect mobilities of $4.0{\times}10^{-3}cm^2$/Vs and $2.0{\times}10^{-3}cm^2$/Vs, respectively, for solution-processed OTFTs.

• Journal of Applied Biological Chemistry
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• v.50 no.4
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• pp.275-280
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• 2007

Dried unripe fruits of Rubus coreanus Miq. were extracted with 80% aqueous MeOH and the concentrated extract was partitioned with EtOAc and $H_2O$. From the EtOAc fraction, four triterpenoids were isolated through repeated silica gel, ODS and Sephadex LH-20 column chromatographies. From the result of physico-chemical data including NMR, MS aud IR, the chemical structures of the compounds were determined as tormentic acid (1), myrianthic acid (2), hovenic acid (3) and 2${\alpha}$,3${\beta}$,19${\beta}$,23-tetrahydroxylolean-12-en-28-oic acid (4). Compounds 3 and 4 were isolated for the first time from this plant. All isolated compounds were evaluated for cytotoxic activity against human colon carcinoma cells using in vitro three-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, compound 3 showed a higher cytotoxicity ($IC_{50}$ = 7.8 ${\mu}M$) than doxorubicin ($IC_{50}$= 50 ${\mu}M$).

• Applied Biological Chemistry
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• v.39 no.6
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• pp.501-505
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• 1996

우리나라에서 오랫동안 적색 및 황색색소원으로 널리 사용하여 왔던 홍화(Carthamus tinctorius)로부터 전통적인 추출방법을 응용한 새로운 방법을 사용하여 적색소를 효과적으로 분리정제하였다. 홍화꽃잎을 물 및 메탄올로 처리하여 황색소를 제거한 다음 건조파쇄하여 0.5 M $Na_2CO_3$로 홍색소를 추출하고 0.5 M citrate 수용액으로 침전시킨 후 cellulose 흡착, Sephadex LH-20 관크로마토그라피로 분리정제하였다. 분리정제된 적색소는 $300^{\circ}C$에서 분해되었고 silica gel TLC 상에서 BAW(n-BuOH : HOAc : $H_2O$=4 : 1 : 5)로 전개하였을 때 $R_f$값이 0.56이었다. 에탄올 용액에 녹인 적색소의 UV/Vis 흡수스펙트럼은 519, 372, 311, 244 nm에서 최대 흡수피크를 나타내었고, IR 스펙트럼은 특히 $3400\;cm^1$ 넓은 영역에서 hydroxyl기에 의한 강한 흡수띠를 보여주었다. $^{1}H$ 및 $^{13}C$ NMR data로 부터 enolized ${\beta}-triketone$, p-hydroxycinnamoyl, methine 및 glucosyl moieties를 확인하였고 그 값을 제시하였다. 이상의 data를 문헌과 비교한 결과 분리한 홍화적색소의 화학구조는 $6-{\beta}-D-glucopyranosyl-2-[[3-{\beta}-D-glucopyranosyl-2,3,4-trihydroxy-5-[3#-(4@-hydroxyphenyl)-1#-oxo-2#-propenyl]-6-oxo-1,4-cyclohexadien-1-yl]methylene]-5,6-dihydroxy-4-[3#-(4@-hydroxyphenyl)-1#-oxo-2#-propenyl]-4-cyclohexene-1,3-dione$인 carthamin으로 확인하였다.

• Korean Journal of Materials Research
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• v.16 no.6
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• pp.367-372
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• 2006

Polytetrafluoroethylene (PTFE) surface was modified for improving hydrophilicity by ion irradiation in environmental gas of $N_2$ and $NH_3$, respectively. The water contact angle onto the PTFE surface increased from $104{\circ}$ to over $140{\circ}$ by Ar ion irradiation in $N_2$ gas. In the case of $NH_3$ as environmental gas, there were a slight increase of contact angle from ion dose of $1{\times}10^{15}\;to\;5{\times}10^{15}\;ions/cm^2$, and its dramatic decrease to the value of 35o at the conditions of ion dose higher than $1{\times}10^{16}\;ions/cm^2$. It was found from SEM results that the surface morphology of PTFE was changed into one with filament structure after Ar ion irradiation in $N_2$ gas environments. On the contrary, Ar ion irradiation in $NH_3$ gas condition induced the PTFE surface with network structure. Hydrogen ion irradiation resulted in a little change of PTFE surface morphology, comparing with the case of Ar ion irradiation. The water contact angle of hydrogen ion irradiated PTFE surface in reactive gas decreased with increment of ion dose. Hydrogen ion irradiation could improve hydrophilicity with little change of surface morphology. It might be considered from FT-IR results that the improvement in wettability of PTFE surface by ion irradiation in $N_2$ and $NH_3$ gases could be due to the hydrophilic groups of NHx bonds.

• Bulletin of the Korean Chemical Society
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• v.21 no.7
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• pp.720-726
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• 2000

The analytic gradient method for the equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) energy has been extended to employ a reduced molecular orbital (MO) space. Not only the innermost core MOs but also some of the outermost virtua l MOs can be dropped in the reduced MO space, and a substantial amount of computation time can be reduced without deteriorating the results. In order to study the magnitudes and trends of the effects of the dropped MOs, the geometries and vibrational properties of the ground and excited states of BF, CO, CN, N2, AlCl, SiS, P2, BCl, AIF, CS, SiO, PN and GeSe are calculated with different sizes of molecular orbital space. The 6-31 G* and the aug-cc-pVTZ basis sets are employed for all molecules except GeSc for which the 6-311 G* and the TZV+f basis sets are used. It is shown that the magnitudes of the drop-MO effects are about $0.005\AA$ in bond lengths and about 1% on harmonic frequencies and IR intensities provided that the dropped MOs correspond to (1s), (1s,2s,2p), an (1s,2s,2p,3s,3p) atomic orbitals of the first, the second, and the third row atoms, respectively. The geometries and vibrational properties of the first and the second excited states of HCN and HNC are calculated by using a drastically reduced virtual MO space as well as with the well defined frozen core MO space. The results suggest the possibility of using a very smalI MO space for qualitative study of valence excited states.

• Journal of the Semiconductor & Display Technology
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• v.8 no.3
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• pp.19-23
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• 2009

We have studied dielectric characteristics of low-k interlayer dielectric materials was fabricated by plasma enhanced chemical vapor deposition (PECVD). BTMSM precursor was introduced with the flow rates from 24 sccm to 32 sccm by 2 sccm step in the constant flow rate of 60 sccm $O_2$. Then, SiOCH thin film deposited at room temperature was annealed at temperature of $400^{\circ}C$ and $500^{\circ}C$ for 30 minutes in vacuum. The vibrational groups of SiOCH thin films were analyzed by FT/IR absorption lines, and the dielectric constant of the low-k SiOCH thin films were obtained by measuring C-V characteristic curves. With the result that FTIR analysis, as BTMSM flow rate increase, relative carbon content of SiOCH thin film increased from 29.5% to 32.2%, and increased by 32.8% in 26 sccm specimen after $500^{\circ}C$ annealing. Dielectric constant was lowest by 2.32 in 26 sccm specimen, and decreased more by 2.05 after $500^{\circ}C$ annealing. Also, leakage current is lowest by $8.7{\times}10^{-9}A/cm^2$ in this specimen. In the result, shift phenomenon of chemical bond appeared in SiOCH thin film that BTMSM flow rate is deposited by 26 sccms, and relative carbon content was highest in this specimen and dielectric constant also was lowest value

• Journal of Applied Biological Chemistry
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• v.61 no.4
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• pp.371-377
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• 2018

The fruits of Panax ginseng were extracted with 80% aqueous MeOH and the concentrates were partitioned into EtOAc, n-BuOH, and $H_2O$ fractions. The repeated $SiO_2$ and octadecyl $SiO_2$ column chromatographies for the EtOAc fraction led to isolation of five ginsenosides. The chemical structures of these compounds were determined as ginsenoside F1 (1), ginsenoside F2 (2), ginsenoside F3 (3), ginsenoside Ia (4), notoginsenoside Fe (5) based on spectroscopic analyses including nuclear magnetic resonance, MS, and infrared. Compounds 2-5 were isolated for the first time from the fruits of P. ginseng in this study. All isolated compounds were evaluated for cytotoxic activities against human cancer cell lines such as HCT-116, SK-OV-3, human cervix adenocarcinoma (HeLa), HepG2, and SK-MEL-5. Among them compounds 2, 4, and 5 showed significant cytotoxicity on cancer cells. Compound 2 exhibited cytotoxicity on SK-MEL-5, HepG2, and HeLa cells with $IC_{50}$ values of 82.8, 86.8, and $78.3{\mu}M$, respectively. Compound 4 showed cytotoxicity on HCT-116, SK-MEL-5, SK-OV-3, HepG2, and HeLa cells with $IC_{50}$ values of 24.5, 25.4, 26.3, 22.0, and $24.9{\mu}M$, respectively. Compound 5 did on SK-MEL-5 cell with $IC_{50}$ value of $81.7{\mu}M$. The cytotoxicity of ginsenoside 2, 4, and 5 isolated from the fruits of Panax ginseng showed strong inhibition effect against on cancer cells, all of which have a glucopyranosyl moiety on C-3.

• Textile Coloration and Finishing
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• v.22 no.2
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• pp.132-139
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• 2010

Sericin pulverization process was applied by freezing-thawing of sericin protein concentration solution and physicochemical properties of sericin/chitosan blended films were investigated. In sericin pulverization process by freezing-thawing method, the refrigeration storage at $4^{\circ}C$ maximized gelling between sericin molecules, which increased 10% of recovery ratio from sericin concentration solution that using ultrafiltration procedure. In physicochemical properties of sericin/chitosan blended films, the maximum load of chitosan (6.7kgf) had higher than that of sericin (1.2kgf), and the elongation of sericin and chitosan had 96% and 34%, respectively. Also FT-IR analysis of sericin/chitosan blended films showed that both sericin and chitosan films had amide I peak (N-H bond) in $1,521cm^{-1}$ and amide II peak (C=O bond) in $1,630cm^{-1}$. In addition, it could confirm compatibility between both materials as indicated by the decrease in the amide I peak's absorption value as chitosan content increases.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.47.1-47.1
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• 2016

We present a preliminary result of search for CO molecular outflows toward a sample of 68 candidate Very Low Luminosity Objects (VeLLOs; Lint ${\leq}0.1L_{\odot}$) to help to understand their physical properties. The sources have been identified using the data at IR to radio wavelengths by M. Kim et al. 2016 toward nearby star-forming regions in the Gould belt. These sources were observed in rotational transitions 2-1 and 3-2 of $^{12}CO$, $^{13}CO$, and $C^{18}O$ molecules with SRAO, CSO, JCMT, and ASTE telescopes. In the beginning of our survey we made a single pointing observation in $^{12}CO$ 2-1 or 3-2 lines for our sample, identifying 53 sources as potential outflow candidates from their line wing features. We made full or partial mapping observations for these candidates with the same lines, finding 33 sources with bipolar or one-sided outflow features. Out of these 33 sources, 6 VeLLOs are previously known sources to have their outflows and 27 VeLLOs are found to be new outflow sources identified from this study. We estimated outflow properties with corrections for excitation temperature, optical depth, and inclination. Their outflow forces range from $8.7{\times}10^{-10}$ to $6.0{\times}10^{-5}M_{\odot}\;km\;s^{-1}yr^{-1}$ with a median value of $3.6{\times}10^{-7}M_{\odot}\;km\;s^{-1}yr^{-1}$, indicating that most of the VeLLOs are less powerful than those for protostars. Their accretion luminosities vary from $9.7{\times}10^{-9}$ to $166L_{\odot}$ with a median value of $0.004L_{\odot}$, implying that most VeLLOs have larger ratios of the accretion luminosity to the internal luminosity but a significant number of VeLLOs have smaller ratios. This result suggests that many of the VeLLOs can be explained with episodic accretion but a significant number of VeLLOs cannot.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.94-94
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• 1998

최근 a-CH:N (hydrogenated amorphous carbon nitride)가 a-CH 보다 팡학적, 기계객성 질이 우수하므로 이에 대한 연구가 활발하게 진행되고 있다. 본 실험에선 원료 가스의 유량 은 5 sccm으로 고정시킨 채 원료가스내의 질소 대 메탄 혼합비 (N2ICHa)훌 O 에서 4 까지 변 화시 키 띤서 DC saddle-field PECVD (plasma enhanced chemical vapour d야Xlsition)훌 이 용하여 a-CH:N 박막융 제작하여, 가스 혼합비가 박막의 미세구조와 광학척 성질에 미치는 영향올 연구하였다. 박막 성장시 진공조 내의 압력온 throttle valve롤 사용하여 90 mTorr로 일정하게 유지하였으며 양극 전압과 기판전업은 각각 500 V, 200 V로 고청하고 상온에서 중 착하였다. a a -step으로 측정 한 a-C:H:N 박막의 두께는 혼합가스내의 질소의 양이 증가할수륙 4800 A에서 2000 A로 두께가 감소하였지만 표면 rot핑비less는 혼합가스내의 질소의 양이 중가할 수록 중가함을 AFM (atomic force mi$\alpha$'0 scopy) 으로 관찰하였다. 박막내의 C와 N의 정량 분석은 RES (Rutherford back scattering s야ctroscopy) 핵공명법을 이용하여 분석하였다. X XPS (X -ray photoelectron spec$\sigma$oscopy) 와 FT-IR (Fo삐er transform-infrared s spectrometry)로 미세구조률 측정한 결과 혼합가스내의 질소의 양이 충가할수록 C-H기는 감 소하였지 만 C르N, N-H기 는 늘어 났다. 또한 PL (photoluminescence) 측정 결과 웬료가스 내 메탄과 질소의 비율이 1:1일 때 최대의 발광올 보였고 UVS (비없 vi이et spec$\sigma$orne$\sigma$y)으 로 측정한 광학쩍 에너지 캡은 혼합비내의 질소의 양이 증가할수록 2.53 eV에서 2.3 eV로 감 소하였다. 이를 결과로부터 원료가스내의 N2ICHa의 중가에 따른 박막의 미세구조 변화와 광학척 생 질의 상관 관계가 고찰될 것이다.