• 제목/요약/키워드: mCP

검색결과 823건 처리시간 0.03초

올레핀중합용 첨단 양이온형 제4족 유기금속 착물 (Novel Cationic Group 4 Metal Alkyl Complexes for Olefin Polymerizations)

  • 김일
    • 한국고분자학회지:고분자과학과기술
    • /
    • 제5권3호
    • /
    • pp.236-253
    • /
    • 1994
  • 양이온형 $d^0\;Cp_2M(R)(L)^+$ 착물과 무염기 $Cp_2M(R)^+$ 착물은 $Cp_2M(R)_2$화합물로부터 쉽게 합성할 수 있다. 이들 친전자성 착물에서는 여러가지 리간드 교환반응, 삽입반응, ${\beta}$-H 제거반응 및 ${\sigma}$-결합 복분해반응이 일어날 수 있다. 일반적으로 $Cp2M(R)(L)^+$ 착물은 불포화도와 전하가 크기때문에 중성의 $Cp_2M(R)(X)$$Cp_2M(R)_2$보다 반응성이 크며 $d^0\;{Cp_2}^*M(R)^+$ (M=제 3족과 란탄계) 착물과 여러가지 반응에서 유사한 거동을 보인다. $Cp_2MX_2$를 기초로하여 합성된 Ziegler-Natta 촉매에 의한 올레핀 중합에서 활성점이 $Cp_2M(R)^+$ 양이온이라는 여러가지 직접적인 증거가 발표되었다. 분리가능한 $Cp_2M(R)(L)^+$ 착물은 올레핀중합에서 높은 활성을 보이며, 유기합성의 관점에서 흥미있는 C-C 재조합반응과 같은 다른 여러가지 반응이 일어날 수 있는 기회를 제공한다.

  • PDF

CpG-DNA induces bacteria-reactive IgM enhancing phagocytic activity against Staphylococcus aureus infection

  • Kim, Te Ha;Kim, Dongbum;Lee, Heesu;Kwak, Min Hyung;Park, Sangkyu;Lee, Younghee;Kwon, Hyung-Joo
    • BMB Reports
    • /
    • 제52권11호
    • /
    • pp.635-640
    • /
    • 2019
  • CpG-DNA triggers the proliferation and differentiation of B cells which results in the increased production of antibodies. The presence of bacteria-reactive IgM in normal serum was reported; however, the relevance of CpG-DNA with the production of bacteria-reactive IgM has not been investigated. Here, we proved the function of CpG-DNA for the production of bacteria-reactive IgM. CpG-DNA administration led to increased production of bacteria-reactive IgM both in the peritoneal fluid and serum through TLR9 signaling pathway. When we stimulated B cells with CpG-DNA, production of bacteria-reactive IgM was reproduced in vitro. We established a bacteria-reactive monoclonal IgM antibody using CpG-DNA stimulated-peritoneal B cells. The monoclonal IgM antibody enhanced the phagocytic activity of RAW 264.7 cells against S. aureus MW2 infection. Therefore, we suggest that CpG-DNA enhances the antibacterial activity of the immune system by triggering the production of bacteria-reactive IgM. We also suggest the possible application of the antibodies for the treatment of antibiotics-resistant bacterial infections.

Kinetic Analysis of CpG-Induced Mouse B Cell Growth and Ig Production

  • Kim, Young-Ha;Lee, Sang-Hoon;Yoo, Yung-Choon;Lee, Jung-Lim;Park, Jong-Hwan;Park, Seok-Rae
    • IMMUNE NETWORK
    • /
    • 제12권3호
    • /
    • pp.89-95
    • /
    • 2012
  • Immune cells express toll-like receptors (TLRs) and respond to molecular patterns of various pathogens. CpG motif in bacterial DNA activates innate and acquired immune systems through binding to TLR9 of immune cells. Several studies reported that CpG can directly regulate B cell activation, differentiation, and Ig production. However, the role of CpG in B cell growth and Ig production is not fully understood. In this study, we analyzed the effect of CpG on the kinetics of mouse B cell viability, proliferation, and Igs production. Overall, CpG enhanced mouse B cell growth and production of Igs in a dose-dependent manner. Unlike LPS, 100 nM CpG (high dose) did not support TGF-${\beta}1$-induced IgA and IgG2b production. Moreover, 100 nM CpG treatment abrogated either LPS-induced IgM or LPS/TGF-${\beta}1$-induced IgA and IgG2b production, although B cell growth was enhanced by CpG under the same culture conditions. We subsequently found that 10 nM CpG (low dose) is sufficient for B cell growth. Again, 10 nM CpG did not support TGF-${\beta}1$-induced IgA production but, interestingly enough, supported RA-induced IgA production. Further, 10 nM CpG, unlike 100 nM, neither abrogated the LPS/TGF-${\beta}1$- nor the LPS/RA-induced IgA production. Taken together, these results suggest that dose of CpG is critical in B cell growth and Igs production and the optimal dose of CpG cooperates with LPS in B cell activation and differentiation toward Igs production.

부분 도핑을 이용한 청색 인광 OLEDs의 전기 및 광학적 특성 (Electrical and Optical Properties of Partially Doped Blue Phosphorescent OLEOs)

  • 서유석;문대규
    • 한국전기전자재료학회논문지
    • /
    • 제22권6호
    • /
    • pp.512-515
    • /
    • 2009
  • We have fabricated blue phosphorescent organic light emitting diodes (PHOLEDs) using a 3,5'-N,N'-dicarbazole-benzene (mCP) host and iridium (III) bis[(4,6-difluorophenyl)-pyridinato-N,$C^{2'}$] picolinate (Flrpic) guest materials, The Flrpic was partially doped into the mCP host layer, for investigating recombination zone, current efficiency, and emission characteristics of the blue PHOLEDs. The recombination of electrons and holes takes place inside the mCP layer adjacent to the mCP/hole blocking layer interface. The best current efficiency was obtained in a device with an emission layer structure of mCP (10 nm)/mCP:Flrpic (20 nm, 10%). The high current efficiency in this device was attributed to the confinement of Ffrpic triplet excitons by the undoped mCP layer with high triplet energy, which blocks diffusion of Ffrpic excitons to the adjacent hole transport layer with a lower triplet energy.

발효 조건이 막걸리 술덧 유래 다당의 면역자극 활성에 미치는 효과 (Effect of Crude Polysaccharide Isolated from Mageoli Mash under Different Fermentation Conditions on Immune-Stimulating Activity)

  • 이영경;남소현;김혜련;조장원;이영철;김영찬;홍희도
    • 한국식품영양과학회지
    • /
    • 제43권12호
    • /
    • pp.1835-1842
    • /
    • 2014
  • 본 연구에서는 가장 대중적인 한국의 전통주 막걸리의 제조과정이 기능성 분획에 미치는 영향을 확인하고자 하였다. Saccharomyces cerevisae 균주별, 발효온도별, 발효기간별로 다르게 만든 막걸리로부터 ethanol 침전법을 이용해 crude polysaccharides(CP-M)를 분리하여 peritoneal macrophage 활성화 효과와 세포 배양액 중의 interleukin(IL)-6와 -12 농도에 미치는 영향을 조사하였다. S. cerevisae 89-1-1, 98-2, 268-3, 113-4의 4가지 효모 중 S. cerevisae 113-4로 발효한 CP-M을 peritoneal macrophage에 $10{\mu}g/mL$ 처리했을 때 세포 배양액 중 nitric oxide(NO) 농도 $33.3{\mu}M$로 가장 높았으며, IL-6와 -12의 농도 역시 116.3 pg/mL와 59.8 pg/mL로 가장 높게 나타났다. S. cerevisae 113-4를 접종하여 온도별로 발효한 발효물에서 분리한 CP-M 중 $25^{\circ}C$에서 발효 후 얻은 CP-M을 peritoneal macrophage 세포에 처리했을 때, NO 농도가 Control 대비 2.7~3.3배, IL-6 농도는 5.7배까지 증가하였다. 그러나 15, 20, $30^{\circ}C$에서 발효하여 얻은 CP-M의 경우 peritoneal macrophage의 NO와 IL-6 생성량에는 Control(무처리구)과 비교하여 영향이 없었다. 발효기간별 영향을 관찰한 결과 5일째 술덧에서 분리한 CP-M에 의한 NO 생성량이 가장 높아 0일째 MCP에 비해 2.2배 증가하였다. 그러나 급격하게 IL-6와 -12의 농도가 감소한 10일째 MCP를 제외하고는 발효기간에 따른 IL-6와 -12의 유의적인 농도 차이는 없었다. 이상의 결과에서 가장 활성이 좋은 발효 조건은 S. cerevisae 113-4를 접종하여 $25^{\circ}C$에서 5일간 발효시킨 술덧의 CP-M이었다. 이때 CP-M의 조성은 neutral sugar 함량 78.6%, acidic polysaccharide 11.6%, 단백질 9.8%였다. 특히 neutral sugar의 구성당 비율은 mannose 47.8 mole%, glucose 29.6 mole%, galactose 12.7 mole%였다. 이상의 결과에서 면역증강 활성이 있는 기능성 조다당 CP-M은 mannose 함량이 높은 yeast 유래의 extracellular polysaccharide로 추정하였다.

발광층 내의 스페이서가 인광 OLED의 효율 및 발광 특성에 미치는 영향 (Effects of Spacer Inserted Inside the Emission Layer on the Efficiency and Emission Characteristics of Phosphorescent Organic Light-emitting Diodes)

  • 서유석;문대규
    • 한국전기전자재료학회논문지
    • /
    • 제27권6호
    • /
    • pp.377-382
    • /
    • 2014
  • We have investigated the effects of spacer layer inserted between blue and red doped emission layers on the emission and efficiency characteristics of phosphorescent OLEDs. N,N'-di-carbazolyl-3,5-benzene (mCP) was used as a host layer. Iridium(III)bis[(4,6-di-fluorophenyl)- pyridinato-N,$C^2$']picolinate (FIrpic) and tris(1-phenyl-isoquinolinato-$C^2$,N)iridium(III) [Ir(piq)3] were used as blue and red dopants, respectively. The emission layer structure was mCP (1-x) nm/mCP:$Ir(piq)_3$ (5 nm, 10%)/mCP (x nm)/mCP:FIrpic (5 nm, 10%). The thickness of mCP spacer layer was varied from 0 to 15 nm. The emission from $Ir(piq)_3$ and the efficiency of the device were dominated by energy transfer from mCP host and FIrpic molecules, and by diffusion of mCP host triplet excitons.

분무성형법에 의해 제조된 $Al-SiC)_p$ 금속기 복합재료의 미세조직과 성질에 관한 연구 (A Study on the Microstructures and Properties of $Al-SiC)_p$ Metal Matrix Composites Fabricated by Spray Forming Process)

  • 김춘근
    • 한국분말재료학회지
    • /
    • 제1권1호
    • /
    • pp.42-51
    • /
    • 1994
  • 6061Al-SiCP metal matrix composite materials(MMCs) were fabricated by injecting SiCP particles directly into the atomized spray. The main attraction of this technique is the rapid fabrication of semi-finished, composite products in a combined atomization, particulate injection(10 $\mu\textrm{m}$, 40 $\mu\textrm{m}$, SiCP) and deposition operation. Conclusions obtained are as follows; The microstructure of the unreinforced spray formed 6061Al alloy consisted of relatively fine(50 $\mu\textrm{m}$) equiaxed grains. By comparision, the microstructure of the I/M materials was segregated and consisted of relatively coarse(150 $\mu\textrm{m}$) grains. The probability of clustering of SiCP particles in co-sprayed metal matrix composites increased it ceramic particle size(SiCP) was reduced and the volume fraction was held constant. Analysis of overspray powders collected from the spray atomization and deposition experiments indicated that morphology of powders were nearly spherical and degree of powders sphercity was deviated due to composite with SiCp particles. Interfacial bonding between matrix and ceramics was improved by heat treatment and addition of alloying elements(Mg). Maximum hardness values [Hv: 165 kg/mm2 for Al-10 $\mu\textrm{m}$ SiCp Hv--159 kg/mm2 for Al-40 $\mu\textrm{m}$SiCp] were obtained through the solution heat treatment at $530^{\circ}C$ for 2 hrs and aging at $178^{\circ}C$, and there by the resistance were improved.

  • PDF

On the spectral rigidity of almost isospectral manifolds

  • Pak, Hong-Kyung
    • 대한수학회보
    • /
    • 제29권2호
    • /
    • pp.237-243
    • /
    • 1992
  • Let (M, g, J) be a closed Kahler manifold of complex dimension m > 1. We denote by Spec(M,g) the spectrum of the real Laplace-Beltrami operator. DELTA. acting on functions on M. The following characterization problem on the spectral rigidity of the complex projective space (CP$^{m}$ , g$_{0}$ , J$_{0}$ ) with the standard complex structure J$_{0}$ and the Fubini-Study metric g$_{0}$ has been attacked by many mathematicians : if (M,g,J) and (CP$^{m}$ ,g$_{0}$ ,J$_{0}$ ) are isospectral then is it true that (M,g,J) is holomorphically isometric to (CP$^{m}$ ,g$_{0}$ ,J$_{0}$ )\ulcorner In [BGM], [LB], it is proved that if (M,J) is (CP$^{m}$ , J$_{0}$ ) then the answer to the problem is affirmative. Tanno ([Ta]) has proved that the answer is affirmative if m .leq. 6. Recently, Wu([Wu]) has showed in a more general sense that if (M, g) and (CP$^{m}$ ,g$_{0}$ ) are (-4/m)-isospectral, m .geq. 4, and if the second betti number b$_{2}$(M) is equal to b$_{2}$(CP$^{m}$ ).

  • PDF

SiCp/6061Al합금복합재료의 시효거동 (Age-Hardening Behavior of SiCp Reinforced 6061 Aluminum Alloy Composites)

  • 안행근;유정희;김석원;우기도
    • 한국재료학회지
    • /
    • 제10권12호
    • /
    • pp.793-798
    • /
    • 2000
  • 석출경화형 6061Al기지합금과 SiC입자크기를 0.7$\mu\textrm{m}$ 및 7.0$\mu\textrm{m}$로 변화시켜 강화한 SiCp/6061Al 합금복합재료의 시효 거동을 경도측정, DSC 시험 및 TEM관찰을 통하여 조사하였다. 17$0^{\circ}C$에서 등온시효시 6061Al기지합금에 비하여 복합화한 0.7$\mu\textrm{m}$SiCp/6061Al합금복합재료 및 7.0$\mu\textrm{m}$SiCP/6061Al합금복합재료에서 최고경도에 도달하는 시간이 짧았으며, 또한 강화재의 크기가 큰 7.0$\mu\textrm{m}$SiCp/6061Al합금복합재료에서 시효촉진이 보다 크게 나타났다. 이것은 복합화 및 SiC입자크기 증가에 따른 전위 밀도 상승에 기인한다. 6061Al기지합금 및 복합재료에서 최고시효처리시의 주강화상은 봉상의 중간상 $\beta$(Mg$_2$Si)이며,$\beta$상 생성의 활성화에너지는 복합화 및 SiG입자크기의 증가에 따라 감소되었다

  • PDF

Evaluation of the Single-Dose Toxicity of Capsaicin Pharmacopuncture in Rats

  • Hwang, Ji Hye;Ku, Jaseung;Jung, Chul
    • Journal of Acupuncture Research
    • /
    • 제37권3호
    • /
    • pp.167-172
    • /
    • 2020
  • Background: This study aimed to assess the toxicity of capsaicin (CP) pharmacopunture in an animal model. Methods: The toxicity of a single-muscular dose of CP (45.45 mg/mL) was evaluated in 6-week-old male and female Sprague-Dawley rats. A total of 20 rats were assigned to 2 groups which were sex and weight matched. All rats acclimatized for 1 week before receiving 1.0 mL of CP (45.45 mg/mL) or normal saline solution (control) intramuscularly. The general condition and mortality of the animals were observed. The rats were sacrificed 2 weeks after CP was administered and histopathology was performed. Results: No abnormal symptoms or deaths were observed, and there was no difference in body weights between the CP and control groups throughout the study. No significant differences in histopathology were observed between the groups. Conclusion: No toxicological changes related to the administration of CP were observed. This study indicated that the safe dose of CP in Sprague-Dawley rats was 1.0 mL of CP (45.45 mg/mL) or less. Further studies are needed to confirm the safety of CP in the human body.