• 제목/요약/키워드: 2a

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다중 피리딘 구조를 가지는 형광염료의 금속 이온 반응성에 대한 연구 (Selective Metal Ion Sensing of Bipyridine-Bisterpyridine containing Fluorescent Dyes)

  • 조혜진;김아롱;정수연;박종승
    • 한국염색가공학회지
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    • 제25권4호
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    • pp.254-261
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    • 2013
  • In this study, we synthesized a new fluorescent polypyridyl dye 2 containing a 2,2'-bipyridine in the center and two 2,2':6',2"-terpyridines at both ends. When exposed to various metal ions, the dye 2 showed selective fluorescence responses. In the presence of $Cu^{2+}$ and $Ni^{2+}$, it exhibited a highly effective fluorescence quenching, leading to large $K_{sv}$ values of up to $10^5$. In response to most other metal ions including $Al^{3+}$, in contrast, its fluorescence changes little, showing a small Ksv value at $10^2$. Meanwhile, the compound 2 revealed a differentiated fluorescence response to $Zn^{2+}$, which is evidenced by a large red shift of > 100 nm. Such a red shift from the ion binding is attributed to the planarization of the bipyridyl unit extending the effective conjugation length in conjunction. A polypyridyl compound will find important usefulness in chemosensor application due to its selective binding to metal ions. Subsequent research concerned with modified derivatives is currently going on, as a way to provide high solubility even after metal-complexing.

One-step Synthesis of Supramolecular Rectangles Starting from ($\eta^5$-Pentamethylcyclopentadienyl)rhodium(III) Aqua Complex

  • 한원석;이순원
    • 한국결정학회:학술대회논문집
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    • 한국결정학회 2002년도 정기총회 및 추계학술연구발표회
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    • pp.27-27
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    • 2002
  • [Cp*Rh(H₂O)₃](OTf)₂ (1) reacts with a stoichiometric amount of A and B [ A = Me₃SiN₃, B = 4,4'-bipridyl, (2a), A = Me₃SiNCO, B = 4,4'-bipridyl (2b)] in acetone at room temperature for 3 h to give the supramolecular complexes [Cp*₄Rh₄(μ-A)₄(μ-B)₂] [A = Me₃SiN₃, B = 4,4'-bipridyl, (2a), A = Me₃SiNCO, B = 4,4'-bipridyl (2b)]. Complexes 2a and 2b have been structurally characterized by X-ray diffraction.

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H2S 제거를 위한 Zeolite와 DETOX의 흡착 특성 비교 연구 (A Study on the comparison on Adsorption characteristics of Zeolite and DETOX for the removal of H2S)

  • 박대석;임지영;조영근;송승준;김진한
    • 한국산학기술학회논문지
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    • 제15권7호
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    • pp.4675-4681
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    • 2014
  • 본 연구는 흡착제 Zeolite 3A와 DETOX에 대하여 $H_2S$의 유입농도와 흡착온도를 공정변수로 하여 포화시간, 흡착량, 흡착속도 등의 $H_2S$ 흡착 제거특성을 평가하기 위하여 수행되었다. $H_2S$의 유입질량유속이 증가함에 따라 Zeolite 3A의 흡착용량은 증가되었으나 포화시간은 감소되었다. 한편 DETOX의 흡착용량과 포화시간은 $H_2S$의 유입질량유속의 증가에 따라 감소되었다. 흡착온도가 상승함에 따라 Zeolite 3A의 흡착용량과 포화시간은 감소한 반면에, DETOX에 대한 이들 값은 증가하였다. DETOX의 $H_2S$흡착용량은 Zeolite 3A의 2.5~16.4배 정도 높게 나타났다. 이는 흡착에서 활성화에너지장벽을 넘어설 충돌빈도는 흡착온도가 증가함에 따라 증가한 것에 기인한 것으로 해석된다. Zeolite 3A와 DETOX에 대하여 $H_2S$의 흡착속도는 $H_2S$의 유입질량유속과 흡착온도가 증가함에 따라 증가하였다. $H_2S$의 흡착속도는 Zeolite 3A가 DETOX의 4배로 나타났다. DETOX는 Zeolite 3A에 비하여 온도 308~318K에서 포화시간은 더욱 길어지고 흡착용량은 더욱 커진다. 바이오가스 중의 $H_2S$제거에 있어서 DETOX는 Zeolite 3A에 비하여 유리한 것으로 나타났다.

Hydroiminoacylation of $\alpha,\omega$-diene with Aldimine by Rh(Ⅰ) and Isomerization of the Terminal Olefin to the Internal Olefin

  • Jun, Chul-Ho;Kang, Jung-Bu;Lim, Yeong-Gweon
    • Bulletin of the Korean Chemical Society
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    • 제14권2호
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    • pp.287-291
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    • 1993
  • Catalytic iminohydroacylation has been achieved by the reaction of aldimine 1 and 1,5-hexadiene (2a) with Wilkinson's complex as catalyst. Compounds 7a, 8a and 9a were obtained as final product after hydrolysis of the resulting iminohydroacylation products 4a, 5a and 6a. Depending on the reactant ratio (2/1), the ratio of products were changed dramatically : As the 2/1 ratio was increased, 7a is the major product after hydrolysis while 8a is the major with an 1/1 ratio of 2/1. The mechanism of the formation of 5a is determined by the reaction of 1 and 2b under the identical reaction conditions. Considering that 5a may not be formed from the hydroiminoacylation of 14a since 5b cannot be formed from that of conjugate diene 14b generated from isomerization of 2b, 5a must be formed from the reaction of 4a and 10 by addition-elimination mechanism.

흰쥐에서 Adriamycin-유발 신독성에 대한 Thromboxane $A_2$ 수용체 길항제인 KT2-962의 효과 (Effects of Selective Thromboxane $A_2$-Receptor Antagonist, KT2-962 on Adriamycin-induced Nephrotoxicity in Rats)

  • 문삼영;이순복;신현진;고현철;엄애선;강주섭
    • Biomolecules & Therapeutics
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    • 제8권3호
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    • pp.241-247
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    • 2000
  • The present study was designed to assess the protective effect of a selective thromboxane $A_2$ receptor antagonist, KT2-962 (KT2) and possible mechanisms of adriamycin(AD)-induced nephrotoxicity in rats. The male Wistar rats were given either of AD (7.5 mg/kg, i.v.) alone in the AD-group (n=5) or in KT2+AD- group (n=5) which is a combination of AD and KT2 (30 mg/kg/day, i.p.) for 10 days from 3 days before and 7 days after AD injection. The body weight, 24-hours urine volume, urine protein and urinary N-acetyl-$\beta$-D-glu-cosaminidase (NAG) activity were measured with an interval of 2 days during 1 week. BUN, serum creatinine and creatinine clearance were measured on the 7th day. KT2 has significantly suppressed AD-induced change of body weight, 24-hours urine volume, urine protein and urinary NAG activity in the KT2+AD-group. The change of BUN, serum creatinine and creatinine clearance were significantly inhibited in the B7T2+AD-group. Based on these results, it is concluded that KT2 prevents AD-induced nephrotoxicity and suggests that endogenous thromboxane A2 may play an important role in AD-induced nephrotoxicity in rats.

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윤대 동구에 대한 Gaussian Apodization (Gaussian apodization for annular pupil)

  • 송영란;이민희;이상수
    • 한국광학회지
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    • 제7권3호
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    • pp.196-199
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    • 1996
  • Gauss 동함수 변조가 이루어진 윤대구경에서 얻어지는 LSF가 전 구경으로 구해지는 LSF( $C_{o}$ $e^{-{\sigma}}$$^{2}$$x^{2}$/)와 같다는 사실을 증명하였다. $C_{o}$ , $C_{1}$은 윤대의 기하학적 구조에 따라서 정해지는 정수이고 진폭 감소율을 .alpha.로 잡을 때 .omega./.root.2<.sigma..leq.(1-.alpha./2.alpha.)$^{1}$2/ .omega.$_{o}$ 의 조건을 얻었다. .alpha.= $e^{-1}$, .lambda.=0.013.mu.m (연 X-선)일 때, .alpha.$_{o}$ '.leq.0.34.alpha.$_{o}$ =1.7cm의 조건을 만족하는 초분해능 윤대구경계로서, l=20cm, .alpha.$_{o}$ =5cm(NA=0.25)일 때, 내경의 최대치 1.7cm보다 약간 작은 .alpha.$_{o}$ '=1.5cm의 반사경계를 제안하였다.

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공황장애와 도파민 D2 수용체 TaqI A 다형성의 관련 (Association between Panic Disorder and Dopamine D2 Receptor TaqI A Polymorphism)

  • 임세원;김범조;오강섭;이민수
    • 대한불안의학회지
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    • 제2권1호
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    • pp.45-49
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    • 2006
  • Puropse : Disturbances of dopaminergic system might be related to the possible mechanism of panic disorder. This study was aimed to examine the association of DRD2 Taq 1 polymorphism and panic disorder. Methods : One hundred and fourteen patients with panic disorder (62 male (54.4%), mean age $40.96{\pm}0.11$ years) and 200 comparison subjects (114 male (57.0%), mean age $35.57{\pm}8.81$ years)were tested for DRD2 TaqI A polymorphism. We excluded panic patients with comorbid alcohol related disorders, bipolar disorders, and any kinds of psychotic disorders because there have been some reports about association of these disease and DRD2 TaqI A polymorphism. Results : There was significant difference in the frequency of the genotype in DRD2 polymorphism between patients and controls (${\chi}^2$=6.09, df=2, p=0.048). The A1+ allele (A1A1 and A1A2) frequency analysis also showed significant association (${\chi}^2$=4.08, df=1, p=0.043). In addition, we observed a more strong and specific association between panic disorder and the A1+ allele of the DRD2 TaqI polymorphism for men (${\chi}^2$=4.71, df=1, p=0.03), but not for women (${\chi}^2$=0.45, df=1, p=0.50). Conclusion : These results in our Korean sample suggest that the DRD2 TaqI A polymorphism may be associated with panic disorder. Furthermore, we found sex-specific association of DRD2 A1 allele with panic disorder.

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무지개송어(Oncorhynchus mykiss) 배양 간세포에서 Vitellogenin 합성에 미치는 Calcium ionophore의 영향 (Effects of Calcium Ionophore on Vitellogenin Production in the Culture of Hepatocytes in the Rinbow Trout, Oncorhynchus mykess)

  • 여인규
    • 한국양식학회지
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    • 제11권2호
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    • pp.241-248
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    • 1998
  • Vitellogenin(VTG) 합성에 미치는 A23187의 영향을 무지개송어의 배양 간세포를 이용하여 실험을 행하였다. 간세포는 2일간 배양한 후, Estradiol-$17^{\beta}$($E_2$, $2{\times}10^{-6}$M) 및 A23187 ($10^{-7)$~$10^{-5}$M)을 첨가하여 7일간 배양하였다. 그리고, $E_2$에 의한 VTG 합성시의 A23187이 미치는 영향에 대해서도 조사하였다. A23187이 미치는 영향에 대해서도 조사하였다. A23187 ($10^{-7)$~$10^{-5}$M)의 첨가에 의해 간세포에서의 VTG 합성은 농도의 증가에 따라 감소하였다.$E_2$에 의해 합성된 VTG는 A 23187 ($10^{-5}$M)의 첨가에 의해 대조군($E_2$만의 첨가)의 약 18%로 유의하게 감소하였다. 그러나,$E_2$제거로는 대조군의 약 47% 밖에 감소되지 않았다. 이러한 결과로 보아, 세포내의 저장 Ca은 번역 단계 또는 번역 후 단계를 조절함으로써, VTG 합성을 조절하는 것으로 추정된다.

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Bacteriophage의 감수성에 의한 수도백엽고병균의 계통분류 (Classification of strains of Xanthomonas oryzae on the basis of their susceptibility against bacteriophage)

  • 이경휘;정하원
    • 한국응용곤충학회지
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    • 제4권
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    • pp.29-32
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    • 1965
  • (1) 한국각지에서 분리한 수도백엽고병균 30균주를 일본의 4계통의 Bacteriophage를 공시하여 분류하여 본 결과 A' 및 B계통의 다음 2종류로 분류하였다. A' 계통 $OP_1$$OP_2$에 감수성이나 $OP_1h$, $OP_1h_2$에는 저항성이었다. B계통 : $OP_1h$, $OP_1h_2$$OP_2$ 감수성이나 $OP_1$에 저항성이었다. A'계통은 $OP_1_2$에 저항성이나 일본의 A 계통은 $OP_1h_2$에도 감수성이었다는 점이 상이하였다. (2) A' 계통균이 국내에 가장 널리 분포하고 있었으며, 계통간의 지역별분포상황은A'계통균이 경기이남에 않았으나 B 계통균은 수원 및 그 이북지방에 분포하고 있었다. (3) 동일품종간에 있어 균의 계통분포는 균일성이 없었다.

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Ag-첨가 Ge2Sb2Te5 박막의 물성 및 고속 결정화 (Characteristics of Ag-added Ge2Sb2Te5 Thin Films and the Rapid Crystallization)

  • 김성원;송기호;이현용
    • 한국전기전자재료학회논문지
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    • 제21권7호
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    • pp.629-637
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    • 2008
  • We report several experimental data capable of evaluating the amorphous-to-crystalline (a-c) phase transformation in $(Ag)_x(Ge_2Sb_2Te_5)_{1-x}$ (x = 0, 0.05, 0.1) thin films prepared by a thermal evaporation. The isothermal a-c structural phase changes were evaluated by XRD, and the optical transmittance was measured in the wavelength range of $800{\sim}3000$ nm using a UV-vis-IR spectrophotometer. A speed of the a-c transition was evaluated by detecting the reflection response signals using a nano-pulse scanner with 658 nm laser diode (power P = $1{\sim}17$ mW, pulse duration t = $10{\sim}460$ ns). The surface morphology and roughness of the films were imaged by AFM. It was found that the crystallization speed was so enhanced with an increase of Ag content. While the sheet resistance of c-phase $(Ag)_x(Ge_2Sb_2Te_5)_{1-x}$ was similar to that of c-phase $Ge_2Sb_2Te_5$ (i.e., $R_c{\sim}10{\Omega}/{\square}$), the sheet resistance of a-phase $(Ag)_x(Ge_2Sb_2Te_5)_{1-x}$ was found to be lager than that of a-phase $Ge_2Sb_2Te_5$, $R_a{\sim}5{\times}10^6{\Omega}{/\square}$. For example, the ratios of $R_a/R_c$ for $Ge_2Sb_2Te_5$ and $(Ag)_{0.1}(Ge_2Sb_2Te_5)_{0.9}$ were approximately $5{\times}10^5$ and $5{\times}10^6$, respectively.