• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3745-3748
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• 2010

Pd(II) p-tolylamide Pd(2,6-$(Ph_2PCH_2)_2C_6H_3$)(NH($C_6H_4Me$-p)) (1) was metathetically prepared by the reaction of Pd(2,6-$(Ph_2PCH_2)_2C_6H_3$)Cl with NaNH($C_6H_4Me$-p). Treatment of 1 with carbon dioxide affords the palladium(II) carbamate Pd(2,6-$(Ph_2PCH_2)_2C_6H_3$)(OC(O)NH($C_6H_4Me$-p)) (2), quantitatively. Complex 2 reacts with HX (X = Cl, OTf) to give Pd(2,6-$(Ph_2PCH_2)_2C_6H_3$)X, $NH_2$(p-Tol) and $CO_2$. Reaction of the palladium(II) carbamate with MeI produced Pd(2,6-$(Ph_2PCH_2)_2C_6H_3$)I along with generation of methyl N-tolylcarbamate MeOC(O)NH($C_6H_4Me$-p), exclusively.

• Bulletin of the Korean Chemical Society
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• 제23권6호
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• pp.845-851
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• 2002

The synthesis of the intramolecular donor - stabilized silyl and germyl complexes of the type ($Cab^c.p) MMe_2X$ (2a:M=Si, X=Cl;2b;M= Ge, X=Cl;2e;M=Si,X=H) was achieved by the reaction of $LiCab^c,p$ (1) with $Me_2SiClX$ and $Me_2GeCl_2$ respectively. The intramolecular M←P interacion in 2a-2c is provided by $^1H$, $13^C.$, $31^P$ and $29^Si$ NMR spectroscopy. The salt elimination reactions of dichlorotetramethyldisilane and -digermane with 1 afforded the $bis(\sigma-carboranylphosphino)disilane$ and disgermane [$(Cab^C.P)MMe_2]_2(4a;M$ = Si;4b: M=Ge). The oxidative addition reaction of 4a-4b with $pd_2(dba)_3CHCl_3afforded$ the bis(silyl)-and bis(germyl)-palladium complexes. The chloro-bridged dipalladium complexes were obtained by the reaction of 2a-2b with $pd_2(dba)_3CHCl_3$ The crystal structures of 5a and 7b were determined by X-ray structural studies.

• Bulletin of the Korean Chemical Society
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• 제20권3호
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• pp.314-320
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• 1999

Several bisphosphine- and bisphosphite-substituted Re-imido complexes have been prepared from Re(NPh)(PPh3)2Cl3, 1, and Re(N-C6H3-i-Pr2)2Cl3(py), 4. Compound 1 reacted with trimethyl phosphate (P(OMe)3) to give a mixture of two isomers,mer,trans-Re(NPh)(P(OMe)3)2Cl3, 2, and fac,cis-Re(NPh)(P(OMe)3)2Cl3, 2a. In this reaction, the mer,trans-isomer is a major product. Complex 1 also reacted with triethylphosphine (PEt3) to exclusively give mertrans-Re(NPh)(PEt3)2Cl3, 3. Compound 4 reacted with trimethylphosphine (PMe3) to give mer,trans-Re(N-C6H3-i-Pr2)(PMe3)2Cl3, 5, which was converted to mer-Re(N-C6H3-i-Pr2)(PMe)(OPMe3)Cl3, 6, on exposure to air. Crystallographic data for 2: monoclinic space group P21/n, a = 8.870(2) Å, b = 14.393(3) Å, c = 17.114(4) Å, β = 101.43(2)°, Z = 4, R(wR2) = 0.0521(0.1293). Crystallographic data for 5: orthorhombic space group P212121, a = 11.307(l) Å, b = 11.802(l) Å, c = 19.193(2) Å, Z = 4, R(wR2) = 0.0250(0.0593). Crystallographic data for 6: orthorhombic space group P212121, a = 14.036(4) Å, b = 16.486(5) Å, c = 11.397(3) Å, Z = 4, R(wR2) = 0.0261(0.0630).

• 한국표면공학회지
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• 제37권2호
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• pp.80-85
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• 2004

Chromium-carbon (Cr-C) and chromium-carbon-phosphorus (Cr-C-P) alloy deposits using trivalent chromium sulfate baths containing potassium formate were prepared to study their current efficiency, hardness change and phase transformations behavior with heat treatment, respectively. The current efficiencies of Cr-C and Cr-C-P alloy deposits increase with increasing current density in the range of 15-35 A/dm$^2$. Carbon content of Cr-C and phosphorous of Cr-C-P layers decreases with increasing current density, whereas, the carbon content of Cr-C-P layer is almost constant with the current density. Cr-C deposit shows crystallization at $400^{\circ}C$ and has (Cr+Cr$_{ 23}$$C_{6}$) phases at $800^{\circ}C$. Cr-C-P deposit shows crystallization at $600^{\circ}C$ and has (Cr+Cr$_{23}$ $C_{6}$$+Cr_3$P) phases at $800^{\circ}C$. The hardness of Cr-C and Cr-C-P deposits after heating treatment for one hour increase up to Hv 1640 and Hv 1540 and decrease about Hv 820 and Hv 1270 with increasing annealing temperature in the range of $400～^{\circ}C$, respectively. The hardness change with annealing is due to the order of occurring of chromium crystallization, precipitation hardening effect, softening and grain growth with temperature. Less decrease of hardness of Cr-C-P deposit after annealing above $700^{\circ}C$ is related to continuous precipitation of $Cr_{23}$ $C_{6}$ and $Cr_3$P phases which retard grain growth at the temperature.

• E2M - 전기 전자와 첨단 소재
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• 제9권9호
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• pp.885-890
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• 1996

Undoped p-type and Te doped n-type GaSb crystals were grown by the vertical Bridgman method. The lattice constant of the GaSb crystals was 6.096.+-.000373.angs.. The carrier concentration, the resistivity, and the carrier mobility measured by the van der Pauw method were p.iden.8*10$^{16}$ c $m^{-3}$ , .rho..iden.0.20 .ohm.-cm, .mu.$_{p}$ .iden.400c $m^{2}$ $V^{-1}$ se $c^{-1}$ for p-type, n.iden.1*10$^{17}$ c $m^{-3}$ , .rho..iden.0.15 .ohm.-cm, .mu.$_{n}$ .iden.500c $m^{2}$ $V^{-1}$ se $c^{-1}$ for n-type at 300K. In case of treatment with metal ion of R $u^{+3}$, P $t^{+4}$, the carrier concentration, resistivity and carrier mobility of the GaSb crystals were p.iden.2*10$^{17}$ c $m^{-3}$ , .rho..iden.0.08.ohm.-cm, .mu.$_{p}$ .iden.420c $m^{2}$ $V^{-1}$ se $c^{-1}$ for p-type, n.iden.2.5*10$^{17}$ c $m^{-3}$ , .rho..iden.0.07.ohm.-cm, .mu.$_{n}$ .iden.520c $m^{2}$ $V^{-1}$ se $c^{-1}$ for n-type respectively. GaSb crystals had a tendency to lower resistivity and higher mobility, for surface treatment with metal ion effectively diminished surface recombination centers.s.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1998년도 한국생물과학협회 학술발표대회
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• pp.360-360
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• 1998

C11, a chloride-containing VK3 analog, acts as a mediator of programmed cell death in SK-Hep-1 cell lines, but its molecular mechanisms linked to cell death are not understood. In this study, we investigated the expression of p21 gene and its relationship to apoptosis induced by C11. In SK -hep-1 cells, the addition of C11 resulted in time-dependent growth suppression and DNA fragmentation characteristics of apoptosis. p21 protein was induced during this process, while the protein level of p53 was not changed at the same condition. This apoptotic cell death with p21 induction was also observed in the Hep3B cells lacking functional p53 after treatment of C11. These results suggest that C11-induced apoptosis is associated with up-regulation of p21 protein in p53-independent pathway. Next, in order to confirm whether the p53-independent p21 induction is required for C11-induced apoptosis, we introduced the p21 gene into Hep3B. Overexpression of p21 did not affect the expression of the bcl-2 gene, but DNA fragmentation and PARa cleavage were significantly increased. These data indicate that p21 is involved in C11-induced apoptosis. Although Bcl-2 has been implicated to interfere with an essential signaling molecule involved in the apoptosis pathway, its molecular mechanism and target molecule are poorly understood. To determine the effects of bcl-2 overexpression on apoptosis and to investigate whether BcI-2 interfers with the p53-independent p21 pathway, we transfected the bcl-2 expression vector into SK - Hep-1 cels. Overexpression of Bcl-2 prevented C11-induced apoptosis. Taken together, C11-induced apoptosis is regulated by p52-independent p21 pathway and bcl-2 may inhibit functional activity of p21, therebe may inhibit the C11-induced apoptosis.ptosis.

• KSBB Journal
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• 제19권1호
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• pp.50-56
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• 2004

본 연구의 목적은 방향족 화한물인 aniline, benzoate, p-hydroxybenzoate를 분해할 수 있는 Delftia sp. JK-2에서 이들 각 기질에서 배양시 다른 종류의 dioxygenases를 분리 정제하고, 정제된 dioxygenases의 특성을 조사하기 위하여 실시하기 위한 것이다. 기질로서 benzoate, aniline, 또는 p-hydroxybenzoate에 따라 분리된 dioxygenases는 각각 catechol 1,2-dioxygenase (C1 ,2O), catechol 2,3-dioxygenase(C2, 3O), 그리고 protocatechuate 4,5-dioxygenase (4,5-PCD)였다. 각 dioxygenases의 특성을 조사하기 위하여 먼저 benzoate, aniline 또는 p-hydroxybenzoate에서 배양한 Delftia sp. JK-2 세포를 초음파 분쇄기로 파쇄하여, ammonium sulfate precipitation, DEAE-sepharose, 그리고 Q-sepharose의 순서로 정제하여 농축하였다. 정제$.$농축된 dioxygenases의 특이 활성도를 보면 C1, 2O는 3.3 unit/mg, C2, 3O는 4.7unit/mg이고, 4,5-PCD는 2.0 unit/mg이다 C1, 2O와 C2, 3O의 기질 특이성 조사에서는 catechol과 4-methylcatechol에서 두 효소 모두 효소 활성이 나타났으며, C1. 2O에서는 3-methylcatechol에서 약간의 활성이 확인되었고, 4,5-PCD는 protocatechuate에서만 효소 활성을 보여주었다. C1l, 2O와 C2, 3O는 3$0^{\circ}C$와 pH 8.0에서 최적의 활성을 나타내는 것으로 조사되었으며, 4,5-PCD는 3$0^{\circ}C$와 pH 7.0에서 최적의 활성이 조사되었다. Delftia sp. JK-2에서 정제된 C1, 2O와 C2, 3O의 효소활성은 Ag$^{+}$, Hg$^{+}$, 그리고 Cu$^{2+}$에 의해 억제되는 것으로 나타났으며, 4,5-PCD의 경우에는 Ag$^{+}$, Hg$^{+}$, 그리고 Cu$^{2+}$ 뿐만 아니라 Fe$^{3+}$ 에 이해서도 효소 활성이 억제되는 것이 확인되었다. C1, 2O, C2, 3O, 4,5-PCD의 분자량은 SDS-PAGE에 의해 각각 60kDa, 35kDa, 62kDa로 측정되었다.

• 생명과학회지
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• 제19권8호
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• pp.1039-1046
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• 2009

다양한 천연물의 합성대사에 관여하는 식물 cytochrome P450 (P450s)은 그 기능적 다양성에도 불구하고, 이들 효소의 광범위한 기질 특이성을 설명해 줄 수 있는 구조분석에 대해서는 충분한 연구가 이루어지지 못하고 있는 실정이다. 식물 p-coumarate 3-hydroxylase (C3H)에 의해 매개되는 효소 반응은 lignin 과 다양한 phenylpropanoid 부산물들의 생합성에 매우 중요한 것으로 여겨지지만, 막 단백질인 C3H의 발현 및 정제가 효과적으로 이루어지지 못하여, 활성을 측정하기 위한 분석방법이 체계화 되지 못하고 있다. C3H의 작용기작과 기질특이성에 대해 폭넓은 이해를 위한 구조분석의 선행단계는 활성을 갖는 C3H를 밀리그램 단위로 분리, 정제하는 실험적 방법을 확립하는 것이라 할 수 있다. 이를 위해, 본 연구에서는 다양한 돌연변이 방법을 도입하여 식물 막단백질 C3H를 대장균 시스템에서 효과적으로 발현 및 정제할 수 있는 시스템을 사용하였다. 변형된 cytochrome P450 C3H ($C3H_{mod}$)을 세포막으로부터 고농도의 염완충용액을 이용하여 계면활성제 없이 추출하였으며, 2단계 chromatography를 통해 활성을 유지한 상태로 분리할 수 있었다. 이러한 실험적 기법은 NMR 및 X-ray crystallography와 같은 구조분석을 통한 C3H의 효과적인 분석에 적용될 수 있을 것이며, 또한 다른 식물 cytochrome P450 단백질의 효과적인 분석에도 적용 될 수 있을 것이다.

• Journal of Animal Science and Technology
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• 제52권2호
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• pp.149-156
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• 2010

통보리 분쇄 사료를 급여 수준별로 5개 처리구(C:무처리구, T1: 10% 첨가, T2: 20%, T3: 30%, T4: 40% 첨가)를 두고, 비육후기 5개월 동안(각 처리 구별 6두, 총 30두 공시) 처리구별로 각각 급여한 후 48시간 육안 관찰 한 그 결과를 요약하면 다음과 같다. 총 채식량(농후사료+조사료)은 T4 (9.96kg) > T1 (9.42kg) > C (9.22kg) > T3 (8.91kg) > T2 (8.51kg) 순으로 높게 나타났다(P<0.05). 채식시간은 T4 > T3 > C > T1 > T2구 순이였으며 (P<0.01), 반추시간은 T4 > T1 > C > T3 > T2구 순으로 나타났다 (P<0.05). 그러나 휴식시간은 반추시간과 반대로 T2 > T1 > C > T3 > T4 순으로 나타났다(P<0.01). 채식시간과 반추시간을 합한 저작 시간은 T4 (392.5 min.) > T3 (331.4 min.) > C (329.4 min) > T1 (327.2 min) > T2 (276.3 min.) 순으로 나타났다(P<0.01). 식괴수, 총 저작수, 식괴당 저작수, 사료가치지수는 각각 190.9개, 9,129.4회, 47.8회, 39.4 (분/kg)으로 T4구가 가장 높게 나타났다(P<0.01). 식괴당 반추시간은 C구가 가장 높고 T3구가 가장 낮게 나타났으며(P<0.05), 분당 식괴수는 T3 가장 높고 C구가 가장 낮게 나타났다(P<0.05). 채식율과 저작효율은 T2구에서 가장 높았지만(P<0.01, 0.05), 반추효율에서는 T1구가 가장 높았다. 그리고 군 행동에서는 휴식(78.5%) > 반추(11.4%) > 채식(10.1%)순으로, 군 행동 중 서서 휴식은 T3 > C > T2 >T1 >T4 구 순으로 높게 나타났다.

• 한국세라믹학회지
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• 제29권10호
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• pp.791-796
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• 1992

SiC(p)-TiC(p) composites were prepared by gas pressure sintering technique. B4C powder and phenolic resin were added as sintering aids by 0.3 wt%-B and 3 wt%-C, TiC powder were dispersed in SiC by 0, 10, 20, 30 and 50 vol%. Flextural strength, fracture toughness and theoretical density of 70 vol% SiC-30 vol% TiC composite sintered at 220$0^{\circ}C$ by gas pressing were 540 MPa, 5.5 MPa.m1/2 and 98.8% respectively.